Sample records for heat commercial refrigeration from the National Library of Energy Beta (NLEBeta)

Note: This page contains sample records for the topic "heat commercial refrigeration" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.

This document is a pre-publication Federal Register final rule regarding the certification of commercialheating, ventilation, and air-conditioning (HVAC), water heating (WH), and refrigeration (CRE) equipment, as issued by the Deputy Assistant Secretary for Energy Efficiency on April 28, 2014.

Improving refrigeration systems for commercial use can enhance both utility load factors and supermarket profits. This workshop has pinpointed research needs in commercialrefrigeration and systems integration for a supermarket environment.

This document is a pre-publication Federal Register notice of proposed rulemaking regarding certification of commercialheating, ventilation, and air-conditioning, water-heating, and refrigeration equipment, as issued by the Deputy Assistant Secretary for Energy Efficiency on February 7, 2014.

This document provides Public Information for Convening Interviews for US Department of Energys Regulatory Negotiations Convening on Commercial Certification for Heating, Ventilating, Air-Conditioning, and Refrigeration Equipment

The purpose of this workshop was to identify the state-of-the-art and determine research needs for improving energy use and demand in commercialrefrigeration applications. Workshop attendees included research and development, technical operations and marketing people from manufacturers of supermarket refrigeration, space conditioning, and energy management systems equipment, and from supermarket chains and electric utilities. Presentations were given on best current practice and research needs from the perspective of each of these industry segments. Working groups identified ten important research, development and equipment demonstration projects to improve the efficiency of refrigerating equipment, heating, ventilating and air-conditioning (HVAC) equipment, and other energy-using systems in supermarkets.

heat recovery from refrigeration machines is a concept which has great potential for implementation in many businesses. If a parallel requirement for refrigeration and hot water exists, the installation of a system to provide hot water as a by...

The commercial sector consumes over 13 quads of primary energy annually. Most of this consumption (two-thirds) meets the energy needs of lighting and heating, ventilation, and air-conditioning. The largest consuming group of the remaining one-third is commercialrefrigeration at about one quad annually (990 trillion Btu), valued at over $7 billion per year to the commercial sector consumer. Potential energy savings are estimated to be about 266 trillion Btu, with consumer savings valued at about $2 billion. This study provides the first known estimates of these values using a bottom-up approach. The authors evaluated numerous self-contained and engineered commercialrefrigeration systems in this study, such as: supermarket central systems, beverage merchandisers, ice machines, and vending machines. Typical physical characteristics of each equipment type were identified at the component level for energy consumption. This information was used to form a detailed database from which they arrived at the estimate of 990 trillion Btu energy consumption for the major equipment types used in commercialrefrigeration. Based on the implementation of the most cost-effective technology improvements for the seven major equipment types, they estimated an annual potential energy savings of 266 trillion Btu. Much of the savings can be realized with the implementation of high-efficiency fan motors and compressors. In many cases, payback can be realized within three years.

US Department of Energy's Regulatory Negotiations Convening on US Department of Energy's Regulatory Negotiations Convening on Commercial Certification for Heating, Ventilating, Air-Conditioning, and Refrigeration Equipment Public Information for Convening Interviews I. What are the substantive issues DOE seeks to address? Strategies for grouping various basic models for purposes of certification; Identification of non-efficiency attributes, which do not impact the measured consumption of the equipment as tested by DOE's test procedure; The information that is certified to the Department; The timing of when the certification should be made relative to distribution in commerce; and Alterations to a basic model that would impact the certification.

This document is a pre-publication Federal Register final rule regarding alternative efficiency determination methods, basic model definition, and compliance for commercial HVAC, refrigeration, and water heating equipment , as issued by the Deputy Assistant Secretary for Energy Efficiency on December 22, 2014. Though it is not intended or expected, should any discrepancy occur between the document posted here and the document published in the Federal Register, the Federal Register publication controls. This document is being made available through the Internet solely as a means to facilitate the public's access to this document.

Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, methods of managing refrigerant charge, and methods for heating and cooling a space and heating water. Various embodiments deliver refrigerant gas to a heat exchanger that is not needed for transferring heat, drive liquid refrigerant out of that heat exchanger, isolate that heat exchanger against additional refrigerant flowing into it, and operate the heat pump while the heat exchanger is isolated. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled or adjusted by controlling how much liquid refrigerant is driven from the heat exchanger, by letting refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and segments of refrigerant conduit can be interconnected with various components.

its capabil- ity to minimize the total cost of energy for a commercialrefrigeration system while multi-zone refrigeration system, consisting of several cooling units that share a common compressor. This corresponds roughly to 2% of the entire electricity consumption in the country. Refrigerated goods constitute

The objective of this project was to determine the potential energy savings associated with improved utilization of waste heat from supermarket refrigeration systems. Existing and advanced strategies for waste heat recovery in supermarkets were analyzed, including options from advanced sources such as combined heat and power (CHP), micro-turbines and fuel cells.

the use of carbon dioxide as refrigerant in supermarket refrigeration systems. The work includes fieldPhD student in Energy Technology, specifically in Commercialrefrigeration systems with CO2 a PhD student in Energy Technology, specifically Commercialrefrigeration systems with CO2

Sample records for heat commercial refrigeration from the National Library of Energy Beta (NLEBeta)

Note: This page contains sample records for the topic "heat commercial refrigeration" from the National Library of EnergyBeta (NLEBeta).
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This document is a pre-publication Federal Register supplemental notice of proposed rulemaking regarding energy conservation standards for alternative efficiency determination methods, basic model definition, and compliance for commercial HVAC, Refrigeration, and Water Heating Equipment, as issued by the Deputy Assistant Secretary for Energy Efficiency on September 18, 2014. Though it is not intended or expected, should any discrepancy occur between the document posted here and the document published in the Federal Register, the Federal Register publication controls. This document is being made available through the Internet solely as a means to facilitate the public's access to this document.

To help businesses save energy and money, the Energy Department today announced new standards aimed at making commercialrefrigerators and freezers. Here are just a few more tips to increase the energy efficiency of these appliances.

Gas-fired commercialrefrigeration is not common today. However, today's and tomorrow's gas engines (internal combustion, Stirling, gas turbines) could power cost-effective refrigeration systems. One key is effectively utilizing the prime mover's reject heat to economic advantage. Another is the capacity control afforded by a variable-speed prime mover. The best example of such a system is comparatively near-term. It serves the large and steady supermarket refrigeration market with an industrial-grade internal combustion engine driving an open-shaft reciprocating compressor. The gas engine's exhaust enables a reciprocating steam engine to boost shaft power by 20%.

A survey has been performed of the technical and patent literature on enhanced heat transfer of refrigerants in pool boiling, forced convection evaporation, and condensation. Extensive bibliographies of the technical literature and patents are given. Many passive and active techniques were examined for pure refrigerants, refrigerant-oil mixtures, and refrigerant mixtures. The citations were categorized according to enhancement technique, heat transfer mode, and tube or shell side focus. The effects of the enhancement techniques relative to smooth and/or pure refrigerants were illustrated through the discussion of selected papers. Patented enhancement techniques also are discussed. Enhanced heat transfer has demonstrated significant improvements in performance in many refrigerant applications. However, refrigerant mixtures and refrigerant-oil mixtures have not been studied extensively; no research has been performed with enhanced refrigerant mixtures with oil. Most studies have been of the parametric type; there has been inadequate examination of the fundamental processes governing enhanced refrigerantheat transfer, but some modeling is being done and correlations developed. It is clear that an enhancement technique must be optimized for the refrigerant and operating condition. Fundamental processes governing the heat transfer must be examined if models for enhancement techniques are to be developed; these models could provide the method to optimize a surface. Refrigerant mixtures, with and without oil present, must be studied with enhancement devices; there is too little known to be able to estimate the effects of mixtures (particularly NARMs) with enhanced heat transfer. Other conclusions and recommendations are offered.

This article provides a look at the history of energy conservation efforts in supermarket refrigeration from World War II to the present and a goal for the future. A supermarket is a low profit margin business, typically netting 1 percent on annual sales. The typical supermarket's annual electric bill equals or exceeds the annual profits. With all of these data, it looked like energy conservation in the supermarket industry was going to be an easy task. Change the lighting to a more energy-efficient system and lower the head pressure and raise the suction pressure in the refrigeration. Any owner, CEO, or general manager who could easily increase his bottom-line profit by 10 to 30 percent would jump at the opportunity, especially when the electric utility was willing to support a portion of the cost for the changes.

In this paper, Life Cycle Climate Performance (LCCP) analysis is used to estimate lifetime direct and indirect carbon dioxide equivalent gas emissions of various refrigerant options and commercialrefrigeration system designs, including the multiplex DX system with various hydrofluorocarbon (HFC) refrigerants, the HFC/R744 cascade system incorporating a medium-temperature R744 secondary loop, and the transcritical R744 booster system. The results of the LCCP analysis are presented, including the direct and indirect carbon dioxide equivalent emissions for each refrigeration system and refrigerant option. Based on the results of the LCCP analysis, recommendations are given for the selection of low GWP replacement refrigerants for use in existing commercialrefrigeration systems, as well as for the selection of commercialrefrigeration system designs with low carbon dioxide equivalent emissions, suitable for new installations.

This paper presents a review of the next generation not-in-kind technologies to replace conventional vapor compression refrigeration technology for household applications. Such technologies are sought to provide energy savings or other environmental benefits for space conditioning, water heating and refrigeration for domestic use. These alternative technologies include: thermoacoustic refrigeration, thermoelectric refrigeration, thermotunneling, magnetic refrigeration, Stirling cycle refrigeration, pulse tube refrigeration, Malone cycle refrigeration, absorption refrigeration, adsorption refrigeration, and compressor driven metal hydride heat pumps. Furthermore, heat pump water heating and integrated heat pump systems are also discussed due to their significant energy saving potential for water heating and space conditioning in households. The paper provides a snapshot of the future R&D needs for each of the technologies along with the associated barriers. Both thermoelectric and magnetic technologies look relatively attractive due to recent developments in the materials and prototypes being manufactured.

The substantial efficiency improvements which have been realized in residential refrigerators over the last twenty years due to implementation of the National Appliance Energy Conservation Act and changing consumer reactions to energy savings give an indication of the potential for improvement in the commercial sector, where few such efficiency improvements have been made to date. The purchase decision for commercialrefrigerators is still focused primarily on first cost and product performance issues such as maximizing storage capacity, quick pulldown, durability, and reliability. The project applied techniques used extensively to reduce energy use in residential refrigeration to a commercial reach-in refrigerator. The results will also be applicable to other commercialrefrigeration equipment, such as refrigerated vending machines, reach-in freezers, beverage merchandisers, etc. The project described in this paper was a collaboration involving the Appliance and Building Technology Sector of TIAX, the Delfield Company, and the U. S. Department of Energy's Office of Building Technologies. Funding was provided by DOE through Cooperative Agreement No. DE-FC26-00NT41000. The program plan and schedule were structured to assure successful integration of the TIAX work on development of efficient design concepts into Delfield's simultaneous development of the Vantage product line. The energy-saving design options evaluated as part of the development included brushless DC and PSC fan motors, high-efficiency compressors, variable-speed compressor technology, cabinet thermal improvement (particularly in the face frame area), increased insulation thickness, a trap for the condensate line, improved insulation, reduced-wattage antisweat heaters, non-electric antisweat heating, off-cycle defrost termination, rifled heat exchanger tubing, and system optimization (selection of heat exchangers, fans, and subcooling, superheat, and suction temperatures for efficient operation). The project started with a thorough evaluation of the baseline Delfield Model 6051 two-door reach-in refrigerator. Performance testing was done to establish a performance baseline which, to meet end-users requirements, would have to be met or exceeded by the high-efficiency refrigerator design. Energy testing was done to establish the baseline energy use. Diagnostic testing such as reverse heat leak testing and insulation conductivity testing was done to evaluate factors contributing to the cabinet load and energy use. Modeling was done to assess the energy savings potential of the energy saving design options. Discussion with vendors and cost modeling was done to assess the manufacturing cost impact of the options. Based on this work, the following group of design options was selected for incorporation in the final refrigerator design: (1) Brushless DC evaporator fans; (2) Improved face frame design; (3) Reduced antisweat heater wattage; (4) Condensate line trap; and (5) Optimized refrigeration system. There was no net cost premium associated with these design changes, leading to a high-efficiency design requiring no payback of any initial additional investment. Delfield incorporated these design options in the Vantage line design and built a first prototype, which was tested at TIAX. Additional design changes were implemented in the transition to manufacturing, based in part on results of initial prototype testing, and a pilot production unit was sent to TIAX for final testing. The energy use of the pilot production unit was 68% less than that of the baseline refrigerator when tested according to the ASHRAE 117 Energy Test Standard. The energy test results for the baseline refrigerator and the two new-design units is shown in Figure ES-1 below. The resulting energy consumption is well below Energy Star and proposed Canadian and California standards levels. Delfield has successfully transitioned the design to production and is manufacturing all configurations of the energy efficient reach-ins at a rate greater than 7,000 per year, with production quantities projec

Nuclear fusion reactors of the Tokamak type will be operated in a pulsed mode requiring the helium refrigerator to remove periodically large heat loads in time steps of approximately one hour. What are the necessary steps for a refrigerator to cope with such load variations?A series of numerical simulations has been performed indicating the possibility of an active refrigerator control with low exergetic losses. A basic comparison is made between the largest existing refrigerator sizes and the size required to service for example the ITER requirements.

1 Scroll compressor modelling for heat pumps using hydrocarbons as refrigerants Paul BYRNE and to install heat pumps in unoccupied spaces. Nevertheless manufacturers keep working on components for hydrocarbons. In the frame of a research project on heat pumps for simultaneous heating and cooling, an R407C

This paper describes the design, construction, and testing of an integrated heat recovery system which has been designed both to enhance the performance of a residential refrigerator and simultaneously to provide preheated water for an electric hot water heater. A commercial, indirect-heated hot water tank was retrofitted with suitable tubing to permit it to serve as a water cooled condenser for a residential refrigerator. This condenser operates in parallel with the air-cooled condenser tubing of the refrigerator so that either one or the other is active when the refrigerator is running. The refrigerator was housed in a controlled-environment chamber, and it was instrumented so that its performance could be monitored carefully in conjunction with the water pre-heating system. The system has been tested under a variety of hot water usage protocols, and the resulting data set has provided significantly insight into issues associated with commercial implementation of the concept. For the case of no water usage, the system was able to provide a 35 C temperature rise in the storage tank after about 100 hours of continuous operation, with no detectable deterioration of the refrigerator performance. Preliminary tests with simulations of high water usage, low water usage, and family water usage indicate a possible 18--20% energy savings for hot water over a long period of operation. Although the economic viability for such a system in a residential environment would appear to be sub-marginal, the potential for such a system associated with commercial-scale refrigeration clearly warrants further study, particularly for climates for which air conditioning heat rejection is highly seasonal.

International agreements mandate the phase-out of many chlorine containing compounds that are used as the working fluid in refrigeration, air-conditioning, and heating equipment. Many of the chemical compounds that have been proposed, and are being used in place of the class of refrigerants eliminated by the Montreal Protocol are now being questioned because of their possible contributions to global warming. Natural refrigerants are put forth as inherently superior to manufactured refrigerants because they have very low or zero global warming potentials (GWPs). Questions are being raised about whether or not these manufactured refrigerants, primarily hydrofluorocarbons (HFCs), should be regulated and perhaps phased out in much the same manner as CFCs and HCFCs. Several of the major applications of refrigerants are examined in this paper and the results of an analysis of their contributions to greenhouse warming are presented. Supermarket refrigeration is shown to be an application where alternative technologies have the potential to reduce emissions of greenhouse gases (GHG) significantly with no clear advantage to either natural or HFC refrigerants. Mixed results are presented for automobile air conditioners with opportunities to reduce GHG emissions dependent on climate and comfort criteria. GHG emissions for hermetic and factory built systems (i.e. household refrigerators/freezers, unitary equipment, chillers) are shown to be dominated by energy use with much greater potential for reduction through efficiency improvements than by selection of refrigerant. The results for refrigerators also illustrate that hydrocarbon and carbon dioxide blown foam insulation have lower overall effects on GHG emissions than HFC blown foams at the cost of increased energy use.

What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler for circulating the fluid in heat exchange relationship with a refrigerant fluid; two refrigerantheat exchangers; one for effecting the heat exchange with the fluid and a second refrigerant-heat exchange fluid heat exchanger for effecting a low pressure ratio of compression of the refrigerant; a rotary compressor for compressing the refrigerant with low power consumption at the low pressure ratio; at least one throttling valve connecting at the inlet side of heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit serially connecting the above elements; refrigerant in the circuit; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant.

Sample records for heat commercial refrigeration from the National Library of Energy Beta (NLEBeta)

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Commercialrefrigeration systems consumed 1.21 Quads of primary energy in 2010 and are known to be a major source for refrigerant charge leakage into the environment. Thus, it is important to study the environmental impact of commercial supermarket refrigeration systems and improve their design to minimize any adverse impacts. The system s Life Cycle Climate Performance (LCCP) was presented as a comprehensive metric with the aim of calculating the equivalent mass of carbon dioxide released into the atmosphere throughout its lifetime, from construction to operation and destruction. In this paper, an open source tool for the evaluation of the LCCP of different air-conditioning and refrigeration systems is presented and used to compare the environmental impact of a typical multiplex direct expansion (DX) supermarket refrigeration systems based on three different refrigerants as follows: two hydrofluorocarbon (HFC) refrigerants (R-404A, and R-407F), and a low global warming potential (GWP) refrigerant (N-40). The comparison is performed in 8 US cities representing different climates. The hourly energy consumption of the refrigeration system, required for the calculation of the indirect emissions, is calculated using a widely used building energy modeling tool (EnergyPlus). A sensitivity analysis is performed to determine the impact of system charge and power plant emission factor on the LCCP results. Finally, we performed an uncertainty analysis to determine the uncertainty in total emissions for both R-404A and N-40 operated systems. We found that using low GWP refrigerants causes a considerable drop in the impact of uncertainty in the inputs related to direct emissions on the uncertainty of the total emissions of the system.

A case study is reviewed on a heat recovery system installed in a meat processing facility to preheat water for the plant hot water supply. The system utilizes waste superheat from the facility's 1,350-ton ammonia refrigeration system. The heat...

The California Energy Resources Conservation and Development Commission has promulgated appliance energy efficiency standards and energy conservation standards for new construction with the objective of reducing energy consumption in the State of California. The following appliance categories are specifically addressed: large capacity air conditioners; commercial water heaters; and commercialrefrigerators and freezers. The tasks that have been performed include: an energy use pattern study for the subject equipment; an examination of the size distribution of commercial air conditioning equipment; an examination of the different types of commercial air conditioning systems; an evaluation of the effectiveness of economizers in reducing commercial air conditioning system energy consumption in California; an examination of the effects of oversizing commercial air conditioners; a detailed study of supermarket refrigeration and air conditioning equipment; an evaluation of the economic feasibility of utilizing air conditioner waste heat to heat water; an assessment of the applicability of existing test procedures for small water heaters to large water heaters; and a brief investigation of the marketing and distribution systems for air conditioning and refrigeration equipment. Results of the efforts are described.

Ester (POE) oils used with HFC refrigerants will break down into acid and alcohol when exposed to heat. Manufacturers have many tools to establish reliability of a product prior to mass production. Units and compressors can be nm on life tests. Prototype...

An analysis is made of the possibility of utilizing waste heat from a proposed gas-turbine fishing-vessel propulsion engine to power a refrigeration plant. On the basis of superior volume, maintenance and reliability, and cost and availability, the ammonia-water absorption system is chosen over the other waste-heat-driven option considered. It is found to be comparable in volume and in maintenance and reliability to the conventional vapor-compression system.

This document is a pre-publication Federal Register final rule regarding test procedures for commercialrefrigeration equipment, as issued by the Deputy Assistant Secretary for Energy Efficiency on April 10, 2014.

Two high-efficiency prime movers for refrigeration are ready for field testing and commercialization. Either machine, combined with other advanced measures, could result in a CFC-free refrigerator using significantly less energy than units meeting the 1993 US efficiency standards. The first design is a linear motor/compressor that manufacturers could substitute for the standard rotating motor/compressor in a conventional refrigerator. The second design is a Stirling-cycle refrigeration machine that is self contained and uses helium gas as the working fluid. The results of prototype testing, the inherent simplicity of both machines, and their virtually frictionless operation point to economical and reliable service. If these features are confirmed in further testing now being conducted by appliance and compressor manufacturers, these machines will be strong candidates for inclusion in super efficient refrigerator designs over the next few years.

This paper reports the investigation results of the possibilities for using pure and mixed refrigerants as working fluids to replace R22 for the DX-SAHP systems. Firstly, pure refrigerants are compared in terms of COP, discharge temperature and mass ... Keywords: direct expansion, heat pump, refrigerant, steady state, simulation

This paper provides an overview of the variable refrigerant flow heat pump computer model included with the Department of Energy's EnergyPlusTM whole-building energy simulation software. The mathematical model for a variable refrigerant flow heat pump operating in cooling or heating mode, and a detailed model for the variable refrigerant flow direct-expansion (DX) cooling coil are described in detail.

1 DYNAMIC MODEL OF AN INDUSTRIAL HEAT PUMP USING WATER AS REFRIGERANT CHAMOUN MARWAN to improve industrial energy efficiency, the development of a high temperature heat pump using water vapor as refrigerant is investigated. Technical problems restraining the feasibility of this industrial heat pump

An emerging DOE-sponsored technology has been deployed. The technology recovers light ends from a catalytic reformer plant using waste heat powered ammonia absorption refrigeration. It is deployed at the 17,000 bpd Bloomfield, New Mexico refinery of Western Refining Company. The technology recovers approximately 50,000 barrels per year of liquefied petroleum gas that was formerly being flared. The elimination of the flare also reduces CO2 emissions by 17,000 tons per year, plus tons per year reductions in NOx, CO, and VOCs. The waste heat is supplied directly to the absorption unit from the Unifiner effluent. The added cooling of that stream relieves a bottleneck formerly present due to restricted availability of cooling water. The 350oF Unifiner effluent is cooled to 260oF. The catalytic reformer vent gas is directly chilled to minus 25oF, and the FCC column overhead reflux is chilled by 25oF glycol. Notwithstanding a substantial cost overrun and schedule slippage, this project can now be considered a success: it is both profitable and highly beneficial to the environment. The capabilities of directly-integrated waste-heat powered ammonia absorption refrigeration and their benefits to the refining industry have been demonstrated.

Ground-source heat pumps can provide an energy-efficient, cost-effective way to heat and cool commercial facilities. While ground-source heat pumps are well established in the residential sector, their application in larger, commercial-style, facilities is lagging, in part because of a lack of experience with the technology by those in decision-making positions. Through the use of a ground-coupling system, a conventional water-source heat pump design is transformed to a unique means of utilizing thermodynamic properties of earth and groundwater for efficient operation throughout the year in most climates. In essence, the ground (or groundwater) serves as a heat source during winter operation and a heat sink for summer cooling. Many varieties in design are available, so the technology can be adapted to almost any site. Ground-source heat pump systems can be used widely in commercial-building applications and, with proper installation, offer great potential for the commercial sector, where increased efficiency and reduced heating and cooling costs are important. Ground-source heat pump systems require less refrigerant than conventional air-source heat pumps or air-conditioning systems, with the exception of direct-expansion-type ground-source heat pump systems. This chapter provides information and procedures that an energy manager can use to evaluate most ground-source heat pump applications. Ground-source heat pump operation, system types, design variations, energy savings, and other benefits are explained. Guidelines are provided for appropriate application and installation. Two case studies are presented to give the reader a sense of the actual costs and energy savings. A list of manufacturers and references for further reading are included for prospective users who have specific or highly technical questions not fully addressed in this chapter. Sample case spreadsheets are provided in Appendix A. Additional appendixes provide other information on the ground-source heat pump technology.

Ground-source heat pumps can provide an energy-efficient, cost-effective way to heat and cool commercial facilities. While ground-source heat pumps are well established in the residential sector, their application in larger, commercial-style, facilities is lagging, in part because of a lack of experience with the technology by those in decision-making positions. Through the use of a ground-coupling system, a conventional water-source heat pump design is transformed to a unique means of utilizing thermodynamic properties of earth and groundwater for efficient operation throughout the year in most climates. In essence, the ground (or groundwater) serves as a heat source during winter operation and a heat sink for summer cooling. Many varieties in design are available, so the technology can be adapted to almost any site. Ground-source heat pump systems can be used widely in commercial-building applications and, with proper installation, offer great potential for the commercial sector, where increased efficiency and reduced heating and cooling costs are important. Ground-source heat pump systems require less refrigerant than conventional air-source heat pumps or air-conditioning systems, with the exception of direct-expansion-type ground-source heat pump systems. This chapter provides information and procedures that an energy manager can use to evaluate most ground-source heat pump applications. Ground-source heat pump operation, system types, design variations, energy savings, and other benefits are explained. Guidelines are provided for appropriate application and installation. Two case studies are presented to give the reader a sense of the actual costs and energy savings. A list of manufacturers and references for further reading are included for prospective users who have specific or highly technical questions not fully addressed in this chapter. Sample case spreadsheets are provided in Appendix A. Additional appendixes provide other information on the ground-source heat pump technology.

The Oak Ridge National Laboratory (ORNL) Power Electronics and Electric Machinery Research Center (PEEMRC) have been developing technologies to address the thermal issues associated with hybrid vehicles. Removal of the heat generated from electrical losses in traction motors and their associated power electronics is essential for the reliable operation of motors and power electronics. As part of a larger thermal control project, which includes shrinking inverter size and direct cooling of electronics, ORNL has developed U.S. Patent No. 6,772,603 B2, ''Methods and Apparatus for Thermal Management of Vehicle Systems and Components'' [1], and patent pending, ''Floating Loop System for Cooling Integrated Motors and Inverters Using Hot Liquid Refrigerant'' [2]. The floating-loop system provides a large coefficient of performance (COP) for hybrid-drive component cooling. This loop (based on R-134a) is integrated with a vehicle's existing air-conditioning (AC) condenser, which dissipates waste heat to the ambient air. Because the temperature requirements for cooling of power electronics and electric machines are not as low as that required for passenger compartment air, this adjoining loop can operate on the high-pressure side of the existing AC system. This arrangement also allows the floating loop to run without the need for the compressor and only needs a small pump to move the liquid refrigerant. For the design to be viable, the loop must not adversely affect the existing system. The loop should also provide a high COP, a flat-temperature profile, and low-pressure drop. To date, the floating-loop test prototype has successfully removed 2 kW of heat load in a 9 kW automobile passenger AC system with and without the automotive AC system running. The COP for the tested floating-loop system ranges from 40-45, as compared to a typical AC system COP of about 2-4. The estimated required waste-heat load for future hybrid applications is 5.5 kW and the existing system could be easily scaleable for this larger load.

Sample records for heat commercial refrigeration from the National Library of Energy Beta (NLEBeta)

Note: This page contains sample records for the topic "heat commercial refrigeration" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
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A refrigeration system is described having a vapor compression cycle utilizing a liquid over-feeding operation with an integrated accumulator-expander-heat exchanger. Hot, high-pressure liquid refrigerant from the condenser passes through one or more lengths of capillary tubing substantially immersed in a pool liquid refrigerant in the accumulator-expander-heat exchanger for simultaneously sub-cooling and expanding the liquid refrigerant while vaporizing liquid refrigerant from the pool for the return thereof to the compressor as saturated vapor. The sub-cooling of the expanded liquid provides for the flow of liquid refrigerant into the evaporator for liquid over-feeding the evaporator and thereby increasing the efficiency of the evaporation cycle. 4 figs.

A refrigeration system having a vapor compression cycle utilizing a liquid over-feeding operation with an integrated accumulator-expander-heat exchanger. Hot, high-pressure liquid refrigerant from the condenser passes through one or more lengths of capillary tubing substantially immersed in a pool liquid refrigerant in the accumulator-expander-heat exchanger for simultaneously sub-cooling and expanding the liquid refrigerant while vaporizing liquid refrigerant from the pool for the return thereof to the compressor as saturated vapor. The sub-cooling of the expanded liquid provides for the flow of liquid refrigerant into the evaporator for liquid over-feeding the evaporator and thereby increasing the efficiency of the evaporation cycle.

AHRI Comments - DOE Verification Testing in Support of Energy Star AHRI Comments - DOE Verification Testing in Support of Energy Star May 9, 2011 P a g e | 1 May 9, 2010 Ms. Ashley Armstrong U.S. Department of Energy 1000 Independence Avenue, SW Washington, DC 20585 RE: DOE Verification Testing in Support of Energy Star Dear Ms. Armstrong: I am writing on behalf of the Air Conditioning, Heating and Refrigeration Institute (AHRI) to address the proposed DOE requirements for verification testing in support of the Energy Star program. AHRI is the trade association representing manufacturers of heating, cooling, and commercialrefrigeration equipment. More than 300 members strong, AHRI is an internationally recognized advocate for the industry, and develops standards for and certifies the performance of many of the

The effects on system efficiency of excess refrigerant line length are calculated for an idealized residential heating and cooling system. By excess line length is meant refrigerant tubing in excess of the 25 R provided for in standard equipment efficiency test methods. The purpose of the calculation is to provide input for a proposed method for evaluating refrigerant distribution system efficiency. A refrigerant distribution system uses refrigerant (instead of ducts or pipes) to carry heat and/or cooling effect from the equipment to the spaces in the building in which it is used. Such systems would include so-called mini-splits as well as more conventional split systems that for one reason or another have the indoor and outdoor coils separated by more than 25 ft. This report performs first-order calculations of the effects on system efficiency, in both the heating and cooling modes, of pressure drops within the refrigerant lines and of heat transfer between the refrigerant lines and the space surrounding them.

A waste heat powered ammonia Absorption Refrigeration Unit (ARU) has commenced operation at the Colorado Refining Company in Commerce City, Colorado. The ARU provides 85 tons of refrigeration at 30 F to refrigerate the net gas/treat gas stream, thereby recovering 65,000 barrels per year of LPG which formerly was flared or burned as fuel. The ARU is powered by the 290 F waste heat content of the reform reactor effluent. An additional 180 tons of refrigeration is available at the ARU to debottleneck the FCC plant wet gas compressors by cooling their inlet vapor. The ARU is directly integrated into the refinery processes, and uses enhanced, highly compact heat and mass exchange components. The refinery's investment will pay back in less than two years from increased recovery of salable product, and CO{sub 2} emissions are decreased by 10,000 tons per year in the Denver area.

A magnetic heat pump apparatus consisting of a solid magnetic refrigerant, gadolinium, and a liquid regenerator column of ethanol and water has been tested. Utilizing a 7T field, it produced a maximum temperature span of 80 K, and in separate tests, a lowest temperature of 241 K and a highest temperature of 328 K. Thermocouples, placed at intervals along the regenerator tube, permitted measurement of the temperature distribution in the regenerator fluid. No attempt was made to extract refrigeration from the device, but analysis of the temperature distributions shows that 34 watts of refrigeration was produced.

global greenhouse gas emissions, and reduce commercial customers' energy bills long-term. As DOE explains efficiency standards. First, energy use related to commercialrefrigeration results in some greenhouse gas emissions. Because the social cost of greenhouse gas emissions may not be fully represented in the price

This study concerns a refrigerator-heat-pump desalination scheme (RHPDS), which allows energy-efficient recovery of fresh water and salt from the sea. In this scheme, a salt-water chamber is continuously refilled with sea water via atmospheric pressure. Sea water is evaporated into a vacuum chamber and the water vapor is condensed on top of a fresh-water chamber. A refrigerator-heat-pump circuit maintains the two water chambers at suitably different operating temperatures and allows efficient recovery of the latent heat of condensation. The scheme is analyzed with special consideration to potential exploitation of renewable energy sources such as solar and wind energy.

A combined power and ejector refrigeration cycle for low temperature heat sources is under investigation in this paper. The proposed cycle combines the organic Rankine cycle and the ejector refrigeration cycle. The ejector is driven by the exhausts from the turbine to produce power and refrigeration simultaneously. A simulation was carried out to analyze the cycle performance using R245fa as the working fluid. A thermal efficiency of 34.1%, an effective efficiency of 18.7% and an exergy efficiency of 56.8% can be obtained at a generating temperature of 395 K, a condensing temperature of 298 K and an evaporating temperature of 280 K. Simulation results show that the proposed cycle has a big potential to produce refrigeration and most exergy losses take place in the ejector. (author)

This project is nearing completion. Since the last progress report (November, 1999), all experimental tests have been completed. Preliminary analysis shows the refrigerant pressure drops through the reversing valve were reduced by an average of about 60{percent}, when compared to traditional reversing valves. Also, the prototype reversing valve reduced the overall coefficient of performance (COP) by an average of only 0.45{percent}.

Although heat pump water heaters are today widely accepted in Japan, where energy costs are high and government incentives for their use exist, acceptance of such a product in the U.S. has been slow. This trend is slowly changing with the introduction of heat pump water heaters into the residential market, but remains in the commercial sector. Barriers to heat pump water heater acceptance in the commercial market have historically been performance, reliability and first/operating costs. The use of carbon dioxide (R744) as the refrigerant in such a system can improve performance for relatively small increase in initial cost and make this technology more appealing. What makes R744 an excellent candidate for use in heat pump water heaters is not only the wide range of ambient temperatures within which it can operate, but also the excellent ability to match water to refrigerant temperatures on the high side, resulting in very high exit water temperatures of up to 82Ã?ÂºC, as required by sanitary codes in the U.S. (Food Code, 2005), in a single pass, temperatures that are much more difficult to reach with other refrigerants. This can be especially attractive in applications where this water is used for the purpose of sanitation. While reliability has also been of concern historically, dramatic improvements have been made over the last several years through research done in the automotive industry and commercialization of R744 technology in residential water heating mainly in Japan. This paper presents the performance results from the development of an R744 commercialheat pump water heater of approximately 35 kW and a comparison to a baseline R134a unit of the same capacity and footprint. In addition, recommendations are made for further improvements of the R744 system which could result in possible energy savings of up to 20 %.

In the United States, energy consumption is increasing most rapidly in the commercial sector. Consequently, the commercial sector is becoming an increasingly important target for state and federal energy policies and also for utility-sponsored demand side management (DSM) programs. The rapid growth in commercial-sector energy consumption also makes it important for analysts working on energy policy and DSM issues to have access to energy end-use forecasting models that include more detailed representations of energy-using technologies in the commercial sector. These new forecasting models disaggregate energy consumption not only by fuel type, end use, and building type, but also by specific technology. The disaggregation of the refrigeration end use in terms of specific technologies, however, is complicated by several factors. First, the number of configurations of refrigeration cases and systems is quite large. Also, energy use is a complex function of the refrigeration-case properties and the refrigeration-system properties. The Electric Power Research Institute`s (EPRI`s) Commercial End-Use Planning System (COMMEND 4.0) and the associated data development presented in this report attempt to address the above complications and create a consistent forecasting framework. Expanding end-use forecasting models so that they address individual technology options requires characterization of the present floorstock in terms of service requirements, energy technologies used, and cost-efficiency attributes of the energy technologies that consumers may choose for new buildings and retrofits. This report describes the process by which we collected refrigeration technology data. The data were generated for COMMEND 4.0 but are also generally applicable to other end-use forecasting frameworks for the commercial sector.

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The model of the perfect continuous counterflow heat exchanger introduced by Frossati et al. to describe the performance of dilution refrigerators is solved rigorously with the proper boundary condition. Unlike the original solution by Frossati et al. the present solution gives the refrigerator cooling power which is in good agreement with experimental data over the entire temperature range. The analysis of the cooling power using the present result allows more detailed evaluation of the refrigerator performance than has been possible with the analysis of the base temperature. An approximate expression for the cooling power is discussed which simplifies the prediction of the cooling rate of a large thermal load such as a copper nuclear?demagnetization stage.

Emerging Technologies Â» Low-GWP Refrigerants Research Project Emerging Technologies Â» Low-GWP Refrigerants Research Project Low-GWP Refrigerants Research Project The U.S. Department of Energy is currently conducting research into low global warming potential (GWP) refrigerants. As concerns about climate change intensify, it is becoming increasingly clear that suitable low-GWP refrigerants will be needed for both new and existing residential and commercialheating, ventilation, air conditioning, and refrigeration (HVAC&R) equipment. Project Description This project seeks to develop alternative refrigerants for HVAC&R equipment. The overall environmental impacts of alternative refrigerants will be assessed using a life cycle climate performance model that accounts for direct emissions associated with refrigerant leaks and indirect

With development of absorption refrigeration technology, the cooling requirement can be met using various optional refrigeration technologies in a CCHP system, including compression refrigeration, steam double-effect absorption refrigeration, steam...

Bangor Hydro Electric Company - Residential and Small Commercial Bangor Hydro Electric Company - Residential and Small CommercialHeat Pump Program (Maine) Bangor Hydro Electric Company - Residential and Small CommercialHeat Pump Program (Maine) < Back Eligibility Commercial Residential Savings Category Heating & Cooling CommercialHeating & Cooling Heat Pumps Program Info State Maine Program Type Utility Rebate Program Rebate Amount Mini-Split Heat Pumps: $600; plus 7.75% financing if necessary Provider Bangor Hydro Electric Company Bangor Hydro Electric Company offers a two-tiered incentive program for residential and small commercial customers. Mini-Split Heat Pumps are eligible for a rebate of $600, as well as a loan to cover the initial cost of the heat pump purchase. Financing is offered at 7.75% APR, for up to

The Robur absorption-refrigeration-water-ammonia (ARWA) cycle is analyzed using Aspen Plus flowsheet simulator. The results are compared with experimental and some manufacturer data reported in the open literature. Among performance parameters analyzed ... Keywords: Aspen, COP, absorption, ammonia, refrigeration, simulation, water

A thermoacousticrefrigerator was built to explore scaling to large heat flux. The refrigerator was constructed according to a modular design so that various stack heat exchanger and resonator sections are easily interchangeable. The resonator is driven by a commercial 10?in. woofer. Initial tests using pure helium gas as the working fluid and steel honeycomb (0.8?mm cell) for the stack pumped 60 W of heat against a 10?°C temperature gradient. Measurements of heat flux and efficiency will be reported as functions of stack structure (e.g. pore size and shape) and will be compared with theoretical predictions.

component of ternary blends and as a blowing agent. Further testing is ongoing to determine its performance characteristics. Since CFC-114 chillers constitute an estimated 1% of the more than 80,000 centrifugal chillers, testing has not been a high..., commercialrefrigerators, ice makers, etc. Some commercial chillers. Some commercialrefrigeration. Marine refrigeration, stationery chillers, ternary blends, blowing agents. 51 RESULTS OF TESTING The testing programs undertaken by the refrigerant...

We explore the dependence of the performance bounds of heat engines and refrigerators on the initial quantum state and the subsequent evolution of their piston, modeled by a quantized harmonic oscillator. Our goal is to provide a fully quantized treatment of self-contained (autonomous) heat machines, as opposed to their prevailing semiclassical description that consists of a quantum system alternately coupled to a hot or a cold heat bath, and parametrically driven by a classical time-dependent piston or field. Here by contrast, there is no external time-dependent driving. Instead, the evolution is caused by the stationary simultaneous interaction of two heat baths (having distinct spectra and temperatures) with a single two-level system that is in turn coupled to the quantum piston. The fully quantized treatment we put forward allows us to investigate work extraction and refrigeration by the tools of quantum-optical amplifier and dissipation theory, particularly, by the analysis of amplified or dissipated phase-plane quasiprobability distributions. Our main insight is that quantum states may be thermodynamic resources and can provide a powerful handle, or control, on the efficiency of the heat machine. In particular, a piston initialized in a coherent state can cause the engine to produce work at an efficiency above the Carnot bound in the linear amplification regime. In the refrigeration regime, the coefficient of performance can transgress the Carnot bound if the piston is initialized in a Fock state. The piston may be realized by a vibrational mode, as in nanomechanical setups, or an electromagnetic field mode, as in cavity-based scenarios.

Variable Refrigerant Flow (VRF) heat pumps are increasingly used in commercial buildings in the United States. Monitored energy use of field installations have shown, in some cases, savings exceeding 30% compared to conventional heating, ventilating, and air-conditioning (HVAC) systems. A simulation study was conducted to identify the installation or operational characteristics that lead to energy savings for VRF systems. The study used the Department of Energy EnergyPlus? building simulation software and four reference building models. Computer simulations were performed in eight U.S. climate zones. The baseline reference HVAC system incorporated packaged single-zone direct-expansion cooling with gas heating (PSZ-AC) or variable-air-volume systems (VAV with reheat). An alternate baseline HVAC system using a heat pump (PSZ-HP) was included for some buildings to directly compare gas and electric heating results. These baseline systems were compared to a VRF heat pump model to identify differences in energy use. VRF systems combine multiple indoor units with one or more outdoor unit(s). These systems move refrigerant between the outdoor and indoor units which eliminates the need for duct work in most cases. Since many applications install duct work in unconditioned spaces, this leads to installation differences between VRF systems and conventional HVAC systems. To characterize installation differences, a duct heat gain model was included to identify the energy impacts of installing ducts in unconditioned spaces. The configuration of variable refrigerant flow heat pumps will ultimately eliminate or significantly reduce energy use due to duct heat transfer. Fan energy is also studied to identify savings associated with non-ducted VRF terminal units. VRF systems incorporate a variable-speed compressor which may lead to operational differences compared to single-speed compression systems. To characterize operational differences, the computer model performance curves used to simulate cooling operation are also evaluated. The information in this paper is intended to provide a relative difference in system energy use and compare various installation practices that can impact performance. Comparative results of VRF versus conventional HVAC systems include energy use differences due to duct location, differences in fan energy when ducts are eliminated, and differences associated with electric versus fossil fuel type heating systems.

Federal purchases of light commercialheating and cooling equipment must be ENERGY STAR®qualified. Federal laws and requirements mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law. This product overview explains how to meet energy-efficiency requirements for Federal purchases of light commercialheating and cooling equipment and how to maximize energy savings throughout products' useful lives.

for Northeast Home Heating Oil Reserve for Northeast Home Heating Oil Reserve DOE Seeks Commercial Storage for Northeast Home Heating Oil Reserve March 14, 2011 - 1:00pm Addthis Washington, DC - The Department of Energy, through its agent, DLA Energy, has issued a solicitation for new contracts to store two million barrels of ultra low sulfur distillate for the Northeast Home Heating Oil Reserve in New York Harbor and New England. Offers are due no later than 9:00 a.m. EDT on March 29, 2011. Of the U.S. households that use heating oil to heat their homes, 69% reside in the Northeast. The Northeast Home Heating Oil Reserve was established by the Energy Policy Act of 2000 to provide an emergency buffer that can supplement commercial fuel supplies in the event of an actual or imminent severe supply disruption. The Reserve can provide supplemental supplies for

Modern Heating Options for Commercial/Institutional Buildings Modern Heating Options for Commercial/Institutional Buildings Speaker(s): Thomas Durkin Date: February 23, 2009 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Moira Howard-Jeweler This seminar presentation will be video-conferenced from our Washington, DC Projects office.) According to USGBC, LBNL, and CBECS data, commercial/institutional buildings use one quarter of all the energy consumed in the US. Depending on the geographic area of the country, heating can be as little as 30% (Houston), or as much as 68% (Minneapolis) of the building total. Mr. Durkin will share his experience in dramatically reducing the heating energy in buildings using a combination of low temperature boilers, heat recovery strategies and a new approach to geo-thermal systems. His data from completed projects shows 50 to 60%

Sample records for heat commercial refrigeration from the National Library of Energy Beta (NLEBeta)

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There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator. 5 figs.

There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator. 5 figs.

Field application tests have been conducted on three 4 to 6-ton commercialheat pump water heater systems in a restaurant, a coin-operated laundry, and an office building cafeteria in Atlanta. The units provide space cooling while rejecting heat...

Radiant heat gain from cooking equipment can significantly impact the air-conditioning load and/or human comfort in a commercial kitchen. This paper presents and discusses updated heat gain data for several types of commercial cooking equipment based on recent testing by gas and electric utility research organizations. The cooking equipment was tested under exhaust-only, wall-canopy hoods. The fundamentals of appliance heat gain are reviewed and the new data are compared with data published in the 1993 ASHRAE Handbook--Fundamentals, chapter 26, nonresidential cooling and heating load calculations. These updated data are now incorporated in the 1997 ASHRAE Handbook--Fundamentals, chapter 28, nonresidential cooling and heating load calculations. The paper also discusses appliance heat gain with respect to sizing air-conditioning systems for commercial kitchens and presents representative radiant factors that may be used to estimate heat gain from other sizes or types of gas and electric cooking equipment when appliance specific heat gain data are not avoidable.

l:--mUSTRIAL AND COMMERCIALHEAT PUMP APPLICATIONS IN THE UNITED STATES Richard C. Niess Dames &. Moore Bethesda, Maryland ABSTRACT The energy crIsIs of 1973 accelerated the develop ment of large-scale heat pumps in the United States. Since... gaining acceptance, including groundwater/geothermal water. INTRODUCTION The large-scale application of heat pumps in the United States had its beginning with the first known installation of an air-to-air heat pump in Reading, Pennsylvania, in 1932...

Variable Refrigerant Flow (VRF) heat pumps are often regarded as energy efficient air-conditioning systems which offer electricity savings as well as reduction in peak electric demand while providing improved individual zone setpoint control. One of the key advantages of VRF systems is minimal duct losses which provide significant reduction in energy use and duct space. However, there is limited data available to show their actual performance in the field. Since VRF systems are increasingly gaining market share in the US, it is highly desirable to have more actual field performance data of these systems. An effort was made in this direction to monitor VRF system performance over an extended period of time in a US national lab test facility. Due to increasing demand by the energy modeling community, an empirical model to simulate VRF systems was implemented in the building simulation program EnergyPlus. This paper presents the comparison of energy consumption as measured in the national lab and as predicted by the program. For increased accuracy in the comparison, a customized weather file was created by using measured outdoor temperature and relative humidity at the test facility. Other inputs to the model included building construction, VRF system model based on lab measured performance, occupancy of the building, lighting/plug loads, and thermostat set-points etc. Infiltration model inputs were adjusted in the beginning to tune the computer model and then subsequent field measurements were compared to the simulation results. Differences between the computer model results and actual field measurements are discussed. The computer generated VRF performance closely resembled the field measurements.

The University of Central Florida/Florida Solar Energy Center, in cooperation with the Electric Power Research Institute and several variable-refrigerant-flow heat pump (VRF HP) manufacturers, provided a detailed computer model for a VRF HP system in the United States Department of Energy's (U.S. DOE) EnergyPlus? building energy simulation tool. Detailed laboratory testing and field demonstrations were performed to measure equipment performance and compare this performance to both the manufacturer's data and that predicted by the use of this new model through computer simulation. The project goal was to investigate the complex interactions of VRF HP systems from an HVAC system perspective, and explore the operational characteristics of this HVAC system type within a laboratory and real world building environment. Detailed laboratory testing of this advanced HVAC system provided invaluable performance information which does not currently exist in the form required for proper analysis and modeling. This information will also be useful for developing and/or supporting test standards for VRF HP systems. Field testing VRF HP systems also provided performance and operational information pertaining to installation, system configuration, and operational controls. Information collected from both laboratory and field tests were then used to create and validate the VRF HP system computer model which, in turn, provides architects, engineers, and building owners the confidence necessary to accurately and reliably perform building energy simulations. This new VRF HP model is available in the current public release version of DOE?s EnergyPlus software and can be used to investigate building energy use in both new and existing building stock. The general laboratory testing did not use the AHRI Standard 1230 test procedure and instead used an approach designed to measure the field installed full-load operating performance. This projects test methodology used the air enthalpy method where relevant air-side parameters were controlled while collecting output performance data at discreet points of steady-state operation. The primary metrics include system power consumption and zonal heating and cooling capacity. Using this test method, the measured total cooling capacity was somewhat lower than reported by the manufacturer. The measured power was found to be equal to or greater than the manufacturers indicated power. Heating capacity measurements produced similar results. The air-side performance metric was total cooling and heating energy since the computer model uses those same metrics as input to the model. Although the sensible and latent components of total cooling were measured, they are not described in this report. The test methodology set the thermostat set point temperature very low for cooling and very high for heating to measure full-load performance and was originally thought to provide the maximum available capacity. Manufacturers stated that this test method would not accurately measure performance of VRF systems which is now believed to be a true statement. Near the end of the project, an alternate test method was developed to better represent VRF system performance as if field installed. This method of test is preliminarily called the Load Based Method of Test where the load is fixed and the indoor conditions and unit operation are allowed to fluctuate. This test method was only briefly attempted in a laboratory setting but does show promise for future lab testing. Since variable-speed air-conditioners and heat pumps include an on-board control algorithm to modulate capacity, these systems are difficult to test. Manufacturers do have the ability to override internal components to accommodate certification procedures, however, it is unknown if the resulting operation is replicated in the field, or if so, how often. Other studies have shown that variable-speed air-conditioners and heat pumps do out perform their single-speed counterparts though these field studies leave as many questions as they do provide answers. The measure

A monitor is described for a refrigeration system including a heat reclaiming system coupled therewith, comprising: a sensor positioned to detect the level of liquid state refrigerant in the system and provide an electrical output signal therefrom; a digital display for displaying the refrigerant level; first circuit means coupling the digital display to the sensor for actuating the digital display; and lockout means coupled with the sensor for deactivating the heat reclaiming system when a preselected refrigerant level is reached.

Abstract The direct-expansion solar-assisted heat pump (DX-SAHP) is widely studied as a refrigeration system, which can supply hot water for domestic use during the whole year. The system refrigerant charge and structure parameters are believed to have a great effect on the cycling thermal performance. The refrigerant mass charge including two-phase and single-phase in heat exchangers and pipes is calculated with distributed and lumped parameter approach mathematical models, respectively. Based on the system simulation program, the refrigerant distribution characteristics and system performance under varied structural parameters are obtained. The mathematical calculation results show that the 70%80% refrigerant charge exists in the condenser and collector; the optimum refrigerant charge, solar collector area, condenser pipe length and condenser internal diameter for the system are 1.651.75 kg, 6.0 m2, 70 m and 9 mm, respectively. In the optimum parameters, the better system performance and feasible cost can be achieved.

This Aging Management Guideline (AMG) describes recommended methods for effective detection and mitigation of age-related degradation mechanisms in commercial nuclear power plant heat exchangers important to license renewal. The intent of this AMG is to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR 54. This AMG is presented in a manner that allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein.

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We have developed closed cycle liquid helium refrigerators using a Joule Thomson circuit precooled by commercially available two staged Gifford Mac Mahon cryocoolers. The Joule Thomson counterflow heat exchangers are modular and have been thermo-hydraulically characterized. Fully automatic cool down and operation are achieved by two pneumatically driven by pass and expansion valves. Several apparatus have been built or are under assembly with cooling power ranging from 100 mW up to 5 Watt, for temperature ranging from 2.8 K up to 4.5 K. A trouble free operation with several warm up and cool down cycles has been proven over 7000 hours.

#12;Overview of DOE-Sponsored Heat Pump Research DOE research activities related to residential and commercialheat pump technology are supported by the Office of Building Energy Research and Development%) allocated to elec- tric and heat-actuated heat pump research. The remaining 15% is allocated to appliance

The demonstration project discussed in this report consisted of two separate programs intended to examine methods of implementing variable-frequency drives (VFDs) to increase the efficiency of supermarket refrigeration racks. The first program examined the optimum control strategy for minimizing the power consumption of medium-temperature parallel compressor racks driven by VFDs. The second program, aimed at developing the optimum control strategy for variable-speed control of supermarket condenser fans.

Heat pump water heaters can provide high-efficiency water heating and supplemental space cooling and dehumidification in commercial buildings throughout the United States. They are particularly attractive in hot, humid areas where cooling loads...

Active magnetic regenerator and method using Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4, where x is equal to or less than 0.5, as a magnetic refrigerant that exhibits a reversible ferromagnetic/antiferromagnetic or ferromagnetic-II/ferromagnetic-I first order phase transition and extraordinary magneto-thermal properties, such as a giant magnetocaloric effect, that renders the refrigerant more efficient and useful than existing magnetic refrigerants for commercialization of magnetic regenerators. The reversible first order phase transition is tunable from approximately 30 K to approximately 290 K (near room temperature) and above by compositional adjustments. The active magnetic regenerator and method can function for refrigerating, air conditioning, and liquefying low temperature cryogens with significantly improved efficiency and operating temperature range from approximately 10 K to 300 K and above. Also an active magnetic regenerator and method using Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4, where x is equal to or greater than 0.5, as a magnetic heater/refrigerant that exhibits a reversible ferromagnetic/paramagnetic second order phase transition with large magneto-thermal properties, such as a large magnetocaloric effect that permits the commercialization of a magnetic heat pump and/or refrigerant. This second order phase transition is tunable from approximately 280 K (near room temperature) to approximately 350 K by composition adjustments. The active magnetic regenerator and method can function for low level heating for climate control for buildings, homes and automobile, and chemical processing.

Active magnetic regenerator and method using Gd{sub 5} (Si{sub x}Ge{sub 1{minus}x}){sub 4}, where x is equal to or less than 0.5, as a magnetic refrigerant that exhibits a reversible ferromagnetic/antiferromagnetic or ferromagnetic-II/ferromagnetic-I first order phase transition and extraordinary magneto-thermal properties, such as a giant magnetocaloric effect, that renders the refrigerant more efficient and useful than existing magnetic refrigerants for commercialization of magnetic regenerators. The reversible first order phase transition is tunable from approximately 30 K to approximately 290 K (near room temperature) and above by compositional adjustments. The active magnetic regenerator and method can function for refrigerating, air conditioning, and liquefying low temperature cryogens with significantly improved efficiency and operating temperature range from approximately 10 K to 300 K and above. Also an active magnetic regenerator and method using Gd{sub 5} (Si{sub x} Ge{sub 1{minus}x}){sub 4}, where x is equal to or greater than 0.5, as a magnetic heater/refrigerant that exhibits a reversible ferromagnetic/paramagnetic second order phase transition with large magneto-thermal properties, such as a large magnetocaloric effect that permits the commercialization of a magnetic heat pump and/or refrigerant. This second order phase transition is tunable from approximately 280 K (near room temperature) to approximately 350 K by composition adjustments. The active magnetic regenerator and method can function for low level heating for climate control for buildings, homes and automobile, and chemical processing. 27 figs.

Five state-of-the-art, production refrigerators from different manufacturers in India were subjected to a variety of appliance rating and performance evaluation test procedures in an engineering laboratory. Cabinet heat loss, compressor calorimeter, high-ambient pull-down, and closed-door energy consumption tests were performed on each unit to assess the current status of commercially available Indian refrigerators and refrigerator component efficiencies. Daily energy consumption tests were performed at nominal line voltages and at 85% and 115% of nominal voltage to assess the effect of grid voltage variations. These test results were also used to indicate opportunities for effective improvements in energy efficiency. A widely distributed ``generic`` computer model capable of simulating single-door refrigerators with a small interior freezer section was used to estimate cabinet heat loss rates and closed door energy consumption values from basic cabinet and refrigeration circuit inputs. This work helped verify the model`s accuracy and potential value as a tool for evaluating the energy impact of proposed design options. Significant differences ranging from 30 to 90% were seen in the measured performance criterion for these ``comparable`` refrigerators suggesting opportunities for improvements in individual product designs. Modeled cabinet heat loadings differed from experimentally extrapolated values in a range from 2--29%, and daily energy consumption values estimated by the model differed from laboratory data by as little as 3% or as much as 25%, which indicates that refinement of the model may be needed for this single-door refrigerator type. Additional comparisons of experimentally measured performance criteria such as % compressor run times and compressor cycling rates to modeled results are given. The computer model is used to evaluate the energy saving impact of several modest changes to the basic Indian refrigerator design.

Commercial-sector conservation analyses have traditionally focused on lighting and space conditioning because of their relatively-large shares of electricity and fuel consumption in commercial buildings. In this report we focus on water heating, which is one of the neglected end uses in the commercial sector. The share of the water-heating end use in commercial-sector electricity consumption is 3%, which corresponds to 0.3 quadrillion Btu (quads) of primary energy consumption. Water heating accounts for 15% of commercial-sector fuel use, which corresponds to 1.6 quads of primary energy consumption. Although smaller in absolute size than the savings associated with lighting and space conditioning, the potential cost-effective energy savings from water heaters are large enough in percentage terms to warrant closer attention. In addition, water heating is much more important in particular building types than in the commercial sector as a whole. Fuel consumption for water heating is highest in lodging establishments, hospitals, and restaurants (0.27, 0.22, and 0.19 quads, respectively); water heating`s share of fuel consumption for these building types is 35%, 18% and 32%, respectively. At the Lawrence Berkeley National Laboratory, we have developed and refined a base-year data set characterizing water heating technologies in commercial buildings as well as a modeling framework. We present the data and modeling framework in this report. The present commercial floorstock is characterized in terms of water heating requirements and technology saturations. Cost-efficiency data for water heating technologies are also developed. These data are intended to support models used for forecasting energy use of water heating in the commercial sector.

The goal was to address the feasibility of frost control by the EHD technique for operating conditions and geometries of significance to refrigeration. The objective of the experimental investigation was to demonstrate by experiment the feasibility of the EHD technique for control of frost on a cold surface under operating conditions of direct significance to refrigeration applications.

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3rd IIR Workshop on Refrigerant Charge Reduction in Refrigerating Systems Corresponding author: P on the refrigerant side and louver fins on the air side. The flat tubes are grouped within a header, to use the heat exchangers with round tubes, such as charge reduction and higher heat transfer efficiency. But a reduced

Optical refrigerators using semiconductor material as a cooling medium, with layers of material in close proximity to the cooling medium that carries away heat from the cooling material and preventing radiation trapping. In addition to the use of semiconducting material, the invention can be used with ytterbium-doped glass optical refrigerators.

Energy Concepts has developed an absorption-augmented system as a cost-effective means of achieving more cooling capacity with a substantial reduction in energy consumption and greenhouse gas emissions for industrial refrigeration. It cuts fuel consumption by 30% by combining an internal combustion engine with a mechanical compression refrigeration system and an absorption refrigeration system. The absorption system is powered by engine waste heat. Conventional industrial refrigeration uses mechanical vapor compression, powered by electric motors, which results in higher energy costs. By the year 2010, the new system could cut fuel consumption by 19 trillion Btu and greenhouse emissions by more than 1 million tons per year.

This document is a pre-publication Federal Register request for information regarding test procedures for commercial water heating equipment, as issued by the Deputy Assistant Secretary for Energy Efficiency (February 21, 2014).

The use of a cryopump and high?pressure internal storage of the cryogen makes it possible to miniaturize a one?shot recyclable 3He refrigerator while at the same time improving its performance. Because of their simplified interface requirements such refrigerators are readily incorporated into existing 4He cryostats allowing a convenient extension of their operating range down to 0.3 K. An analysis of the parameters describing refrigerator performance (condensation time heat transfer to the 4He bath lifetime and refrigeration power) leads to the definition of an optimized refrigerator. Measured performance characteristics of a miniature [2?l standard temperature and pressure (STP) of 3He] refrigerator used in laboratory and stratospheric balloon?borne experiments are given.

adsorbents in heat pump cycles: 1. A high usable refrigerant mass per unit mass of adsorbent. 2. A high energy of adsorption and desorption. 3. Heat flows and composition changes occur at constant temperature. The advantages of complex compounds... 2. Useable refrigerant densities. Summarizing, complex compound exhibit inherent characteristics which make them ideal adsorbents in heat pump cycles: 1. A high usable refrigerant mass per unit mass of adsorbent. 2. A high energy of adsorption...

The bibliography contains selected patents concerning solar heat collector apparatus and systems. Building panels, air conditioning systems, chemical heat pumps, refrigeration systems, and controls are discussed. Applications include residential and commercial building space and water heating, greenhouse heating, and swimming pool heating. (Contains 250 citations and includes a subject term index and title list.)

This document is a pre-publication Federal Register notice of public meeting regarding energy conservation standards for walk-in coolers and freezers; Air-Conditioning, Heating, & Refrigeration Institute petition for reconsideration, as issued by the Deputy Assistant Secretary for Energy Efficiency on September 23, 2014. Though it is not intended or expected, should any discrepancy occur between the document posted here and the document published in the Federal Register, the Federal Register publication controls. This document is being made available through the Internet solely as a means to facilitate the public's access to this document.

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Combined Heat and Power (CHP) systems simultaneously deliver electric, thermal and mechanical energy services and thus use fuel very efficiently. Today's small-scale CHP systems already provide heat, cooling and electricity at nearly twice the fuel efficiency of heat and power based on power remote plants and onsite hot water and space heating. In this paper, the authors have refined and extended the assessments of small-scale building CHP previously done by the authors. They estimate the energy and carbon savings for existing small-scale CHP technology such as reciprocating engines and two promising new CHP technologies--microturbines and fuel cells--for commercial buildings. In 2010 the authors estimate that small-scale CHP will emit 14--65% less carbon than separate heat and power (SHP) depending on the technologies compared. They estimate that these technologies in commercial buildings could save nearly two-thirds of a quadrillion Btu's of energy and 23 million tonnes of carbon.

to Complete Fill of Northeast Home to Complete Fill of Northeast Home Heating Oil Reserve DOE Seeks Commercial Storage to Complete Fill of Northeast Home Heating Oil Reserve August 26, 2011 - 1:00pm Addthis Washington, DC - The Department of Energy (DOE), through its agent DLA Energy, has issued a solicitation seeking commercial storage contracts for the remaining 350,000 barrels of ultra low sulfur distillate needed to complete the fill of the Northeast Home Heating Oil Reserve. Offers are due no later than 9:00 a.m., August 31, 2011. Earlier this year, DOE sold its entire inventory of heating oil stocks with plans to replace it with cleaner burning ultra low sulfur distillate. New storage contracts were awarded in August 2011 for 650,000 barrels, and awards from this solicitation will complete the fill of the one million

This paper describes extensive tests performed on a 3-ton R-22 split heat pump in heating mode. The tests contain 150 steady-state performance tests, 18 cyclic tests and 18 defrost tests. During the testing work, the refrigerant charge level was varied from 70 % to 130% relative to the nominal value; the outdoor temperature was altered by three levels at 17 F (-8.3 C), 35 F (1.7 C) and 47 F (8.3 C); indoor air flow rates ranged from 60% to 150% of the rated air flow rate; and the expansion device was switched from a fixed-orifice to a thermal expansion value. Detailed performance data from the extensive steady state cyclic and defrost testing performed were presented and compared.

A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit. 1 fig.

A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit.

The present invention is an apparatus and method for de-superheating a primary refrigerant leaving a compressor wherein a secondary refrigerant is used between the primary refrigerant to be de-superheated. Reject heat is advantageously used for heat reclaim. 7 figs.

In a mucilage glue fiber factory, the design of the refrigeration system takes into account the characteristics of mucilage glue fiber production and fully uses the refrigeration compressor heat to economize energy and reduce the production cost...

Convening Report on Certification of Commercial HVAC and CRE Products, October 2, 2012 Convening Report on Certification of Commercial HVAC and CRE Products, October 2, 2012 1 U.S. DEPARTMENT OF ENERGY CONVENING REPORT ON THE FEASIBILITY OF A NEGOTIATED RULEMAKING TO REVISE THE CERTIFICATION PROGRAM FOR COMMERCIALHEATING, VENTILATING AIR CONDITIONING AND COMMERCIALREFRIGERATION EQUIPMENT October 2, 2012 Alan W. Strasser, Esq., MA Convener

In temperate climatic zones, solar air heaters can reduce heating loads, and increase winter ventilation rates thereby improving inside air quality and livestock performance without additional fuel input. A heat balance was carried out to measure bird heat production under field conditions on two commercial broiler barns to evaluate the impact of solar heated ventilation air on bird performance, and identify strategies to reduce winter heating load. Located 40 km east of Montreal, Canada, the experimental broiler barns were identically built with three floors housing 6500 birds per floor in an all-in all-out fashion. Equipped with solar air pre-heaters over their fresh air inlets, the barns were instrumented to monitor inlet, inside and outside air conditions, ventilation rate and heating system operating time. The effects on bird performance were observed from November 2007 to March 2009 by alternating their operation between the barns. The measured sensible and total heat productions of 4.5 W and 8.4 W, respectively, for 1 kg birds corresponded to laboratory measured values. Bird performance was not affected by the solar air pre-heaters which increased the ventilation rate above normal during only 20% of the daytime period. Room air temperature stratification resulted in 2040 kW of heat losses during the winter, representing 25% of the total natural gas heat load. Because inside air moved directly to the fans, large and rapid increases in ventilation inlet air temperature, produced by the solar air pre-heaters, resulted in further heat losses equivalent to 15% of the solar energy recovered. Sustainable energy management in livestock barns requiring heating should incorporate an air mixing system to eliminate air temperature stratification and improve fan flows.

In this article we summarize experimental work on cryogen-free 3He/4He dilution refrigerators which, in addition to the dilution refrigeration circuit, are equipped with a 4He-1K-stage. This type of DR becomes worth considering when high cooling capacities are needed at T ~ 1 K to cool cold amplifiers and heat sink cables. In our application, the motivation for the construction of this type of cryostat was to do experiments on superconducting quantum circuits for quantum information technology and quantum simulations. In other work, DRs with 1K-stage were proposed for astro-physical cryostats. For neutron scattering research, a top-loading cryogen-free DR with 1K-stage was built which was equipped with a standard commercial dilution refrigeration insert. Cooling powers of up to 100 mW have been reached with our 1K-stage, but higher refrigeration powers were achieved with more powerful pulse tube cryocoolers and higher 4He circulation rates in the 1K-loop. Several different versions of a 1K-loop have been test...

Evaporative system for water and beverage refrigeration in hot countries A Saleh1 and MA Al-Nimr2 1 Abstract: The present study proposes an evaporative refrigerating system used to keep water or other are found to be consistent with the available literature data. Keywords: evaporative refrigeration, heat

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The invention is a direct contact refrigerant cooling system using a refrigerant floating loop having a refrigerant and refrigeration devices. The cooling system has at least one hermetic container disposed in the refrigerant floating loop. The hermetic container has at least one electronic component selected from the group consisting of capacitors, power electronic switches and gating signal module. The refrigerant is in direct contact with the electronic component.

. The technology was tested in similar days in terms of temperature and solar insolation. The relevant variables that were monitored were the heat flux across the walls of the simulators and temperatures, including surface and indoor air temperatures. Other...

The thermodynamic performance of real irreversible cooling and refrigeration systems (chillers) can be summarized in simple rectangular temperature-entropy diagrams in analogy to classic pedagogical examples for idealized reversible devices. The key to translating complex dissipative losses into this graphical framework is the process average temperaturea factor that can be calculated from nonintrusive experimental measurements for converting entropy production into lost work. An uncomplicated thermodynamic model is used to transform the governing chiller performance equations into an easily-interpreted graph. Examples based upon actual data from commercial work-driven (reciprocating) and heat-driven (absorption) chillers are presented and are used to highlight the predominance of internal dissipation in determining chiller efficiency. With the thermodynamic diagram representation the relative roles of each irreversibility source as well as the reversible and endoreversible limits become transparent.

This study of the service life of water-loop heat pump compressors in commercial office buildings, using data gathered from the service records of one heat pump service contractor, focused on the replacement of compressors in small console ( perimeter'') water-loop heat pumps and in larger vertical and horizontal ( core'') units. A statistical methodology for dealing with censored data was developed for this study which is an extension of the methodologies used in other EPRI studies of heat pump and heat pump compressor life. By extrapolating a Weibull distribution curve fitted to the data, the median service life of the sample of perimeter unit compressors (the age at which 50% of the original population of compressors would be expected to have been replaced) was estimated to be 47 years. The median service life of a sample that excluded compressors with a known manufacturing defect was estimated to be 69 years. Core unit compressor replacements were analyzed in the same manner. Extrapolation of a Weibull distribution yielded an estimated median service life of core unit compressors of 12 years. As with the perimeter unit compressors, there was an identified manufacturing defect. When the compressors with the identified fault were excluded from the sample and the data reanalyzed, the median service life for the compressors in the remainder of the buildings was estimated to be 18 years.

This document is a pre-publication Federal Register request for information regarding energy conservation standards for commercial water heating equipment, as issued by the Deputy Assistant Secretary for Energy Efficiency on October 10, 2014. Though it is not intended or expected, should any discrepancy occur between the document posted here and the document published in the Federal Register, the Federal Register publication controls. This document is being made available through the Internet solely as a means to facilitate the public's access to this document.

UES - Commercial Energy Efficiency Rebate Program UES - Commercial Energy Efficiency Rebate Program UES - Commercial Energy Efficiency Rebate Program < Back Eligibility Commercial Industrial Local Government Schools State Government Savings Category Heating & Cooling CommercialHeating & Cooling Cooling Other Home Weatherization Sealing Your Home Design & Remodeling Windows, Doors, & Skylights Construction Heat Pumps Appliances & Electronics Commercial Lighting Lighting Maximum Rebate 85% of incremental costs up to $10,000 per customer per year. For customers who have a demand load of 500KW or greater, the cap is increased to $50,000 per year for each year that the program is in effect. Program Info Start Date 1/1/2009 State Arizona Program Type Utility Rebate Program Rebate Amount Refrigerator Doors: $120/door

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern.

BEETIT Project: UMD is developing an energy-efficient cooling system that eliminates the need for synthetic refrigerants that harm the environment. More than 90% of the cooling and refrigeration systems in the U.S. today use vapor compression systems which rely on liquid to vapor phase transformation of synthetic refrigerants to absorb or release heat. Thermoelastic cooling systems, however, use a solid-state materialan elastic shape memory metal alloyas a refrigerant and a solid to solid phase transformation to absorb or release heat. UMD is developing and testing shape memory alloys and a cooling device that alternately absorbs or creates heat in much the same way as a vapor compression system, but with significantly less energy and a smaller operational footprint.

The results presented here were obtained during Phase 4 of the first CRADA, which had the specific objective of determining the lifetime of superinsulations when installed in simulated refrigerator doors. The second CRADA was established to evaluate and test design concepts proposed to significantly reduce energy consumption in a refrigerator-freezer that is representative of approximately 60% of the US market. The stated goal of this CRADA is to demonstrate advanced technologies which reduce, by 50%, the 1993 National Appliance Energy Conservation Act (NAECA) standard energy consumption for a 20 ft{sup 3} (570 L) top-mount, automatic-defrost, refrigerator-freezer. For a unit this size, the goal translates to an energy consumption of 1.003 kWh/d. The general objective of the research is to facilitate the introduction of efficient appliances by demonstrating design changes that can be effectively incorporated into new products. In previous work on this project, a Phase 1 prototype refrigerator-freezer achieved an energy consumption of 1.413 kWh/d [Vineyard, et al., 1995]. Following discussions with an advisory group comprised of all the major refrigerator-freezer manufacturers, several options were considered for the Phase 2 effort, one of which was cabinet heat load reductions.

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A test refrigerator based on the modified Reverse Brayton cycle has been developed in the Chinese Academy of Sciences recently. To study the behaviors of this test refrigerator, a dynamic simulation has been carried out. The numerical model comprises the typical components of the test refrigerator: compressor, valves, heat exchangers, expander and heater. This simulator is based on the oriented-object approach and each component is represented by a set of differential and algebraic equations. The control system of the test refrigerator is also simulated, which can be used to optimize the control strategies. This paper describes all the models and shows the simulation results. Comparisons between simulation results and experimental data are also presented. Experimental validation on the test refrigerator gives satisfactory results.

An experimental study was conducted to quantify the effect of several installation items on the high outdoor ambient temperature performance of air conditioners. These installation items were: improper amount of refrigerant charge, reduced...

A computer model has been developed that can predict the performance of supermarket refrigeration equipment to within 3% of field test measurements. The Supermarket Refrigeration Energy Use and Demand Model has been used to simulate currently available refrigerants R-12, R-502 and R-22, and is being further developed to address alternative refrigerants. This paper reports that the model is expected to be important in the design, selection and operation of cost-effective, high-efficiency refrigeration systems. It can profile the operation and performance of different types of compressors, condensors, refrigerants and display cases. It can also simulate the effects of store humidity and temperature on display cases; the efficiency of various floating head pressure setpoints, defrost alternatives and subcooling methods; the efficiency and amount of heat reclaim from refrigeration systems; and the influence of other variables such as store lighting and building design. It can also be used to evaluate operational strategies such as variable-speed drive or cylinder unloading for capacity control. Development of the model began in 1986 as part of a major effort, sponsored by the U.S. electric utility industry, to evaluate energy performance of then conventional single compressor and state-of-the-art multiplex refrigeration systems, and to characterize the contribution of a variety of technology enhancement features on system energy use and demand.

Abstract: The principal market for micro-CHP is as a replacement for gas boilers in the 18 million or so existing homes in the UK currently provided with gas-fired central heating systems. In addition there are a significant number of potential applications of micro-CHP in small commercial and residential buildings. In order to gain the optimum benefit from micro-CHP, it is essential to ensure that an appropriate technology is selected to integrate with the energy systems of the building. This chapter describes the key characteristics of the leading micro-CHP technologies, external and internal combustion engines and fuel cells, and how these align with the relevant applications.

This study focuses on ``other`` end-uses category. The purpose of this study was to determine the relative importance of energy end-use functions other than HVAC and lighting for commercial buildings, and to identify general avenues and approaches for energy use reduction. Specific energy consuming technologies addressed include non-HVAC and lighting technologies in commercial buildings with significant energy use to warrant detailed analyses. The end-uses include office equipment, refrigeration, water heating, cooking, vending machines, water coolers, laundry equipment and electronics other than office equipment. The building types include offices, retail, restaurants, schools, hospitals, hotels/motels, grocery stores, and warehouses.

The economic evaluation of residential and commercial solar heating and hot water systems is presented. Commercial systems are further categorized as taxable and non-taxable applications in recognition of the effect of Federal and state tax incentives and disincentives for solar energy systems. The economic evaluation of each system type is performed utilizing two distinct methods of analysis. The economic analyses follow a brief description of each method. The Cash Flow Analyses provide insight into the short and long term effects of a solar investment on the budget of the solar energy system purchaser while the Return-On-Investment Analyses provide an appropriate method of measuring the attractiveness of a solar investment in comparison to alternative long term investments. Utilizing a typical system for each system type and application the Cash Flow and Return-On-Investment Analyses are presented. The sensitivity of the results on the numerous variables in the economic analyses is shown. Maps provide a graphic display of the results of the economic analysis of typical systems using Federal and state tax credits and average state conventional fuel costs for each system type. Conclusions based on the economic analyses performed and a thorough discussion of the present status of the data required for the complete economic evaluation of solar energy systems are summarized. The current availability and limitations of data and requirements for further work in this area are discussed.

outside the buildings for devices having the refrigerant charge of small heat pumps for space heatingPaper No. 206 10th IIR Gustav Lorentzen Conference on Natural Refrigerants, Delft, The Netherlands by subcooling of the refrigerant in the cold water tank (not used for cooling during winter). The water tank

A compression-evaporation refrigeration system, wherein gaseous compression of the refrigerant is provided by a standing wave compressor. The standing wave compressor is modified so as to provide a separate subcooling system for the refrigerant, so that efficiency losses due to flashing are reduced. Subcooling occurs when heat exchange is provided between the refrigerant and a heat pumping surface, which is exposed to the standing acoustic wave within the standing wave compressor. A variable capacity and variable discharge pressure for the standing wave compressor is provided. A control circuit simultaneously varies the capacity and discharge pressure in response to changing operating conditions, thereby maintaining the minimum discharge pressure needed for condensation to occur at any time. Thus, the power consumption of the standing wave compressor is reduced and system efficiency is improved.

cost, a large component of which is energy-related. Existing system operation must be analyzed to optimize energy consumption while still meeting cooling load requirements. Refrigerant properties, which form the basis for such calculations, have... to illustrate the application of the program to problems in design and operation of refrigeration systems. INTRODUCTION Thermodynamic analysis of refrigeration systems is important in a variety. of industrial; commercial, and building-related applications...

The Energy Policy and Conservation Act (EPCA) as amended by the Energy Policy Act of 1992 (EPACT) establishes that the U.S. Department of Energy (DOE) regulate efficiency levels of certain categories of commercialheating, cooling, and water-heating equipment. EPACT establishes the initial minimum efficiency levels for products falling under these categories, based on ASHRAE/IES Standard 90.1-1989 requirements. EPCA states that, if ASHRAE amends Standard 90.1-1989 efficiency levels, then DOE must establish an amended uniform national manufacturing standard at the minimum level specified in the amended Standard 90.1 and that it can establish higher efficiency levels if they would result in significant additional energy savings. 011Standard 90.1-1999 increases minimum efficiency levels for some of the equipment categories covered by EPCA 92. DOE conducted a screening analysis to determine the energy-savings potential for EPACT-covered products meet and exceeding these levels. This paper describes the methodology, data assumptions, and results of the analysis.

The process for the cogeneration of electricity and commercially saleable refrigeration by expanding pressurized pipeline gas with the performance of work is described which comprises: injecting methanol into the pipeline gas; passing the pipeline gas containing the methanol through a turbo-expander coupled to an electrical generator to reduce the pressure of the pipeline gas at least 100 psi but not reducing the pressure enough to drop the temperature of the resulting cold expanded gas below about - 100/sup 0/F; separating aqueous methanol condensate from the cold expanded gas and introducing the condensate into a distillation column for separation into discard water and recycle methanol for injection into the pipeline gas; recovering the saleable refrigeration from the cold expanded gas; adding reboiler heat to the distillation column in an amount required to warm the expanded gas after the recovery of the saleable refrigeration therefrom to a predetermined temperature above 32/sup 0/F; and passing the expanded gas after the recovery of the saleable refrigeration therefrom in heat exchange with methanol vapor rising to the top of the distillation column to condense the methanol vapor so that liquid methanol is obtained partly for reflux in the distillation column and partly for the recycle methanol and simultaneously the expanded gas is warmed to the predetermined temperature above 32/sup 0/F.

A thermoacoustic device having a thermal stack made from a piece of porous material which provides a desirable ratio of thermoacoustic area to viscous area, which has a low resistance to flow, which minimizes acoustic streaming and which has a high specific heat and low thermal conductivity is disclosed. The thermal stack is easy and cheap to form and it can be formed in small sizes. Specifically, in one embodiment, a thermal stack which is formed by the natural structure of a porous material such as reticulated vitreous carbon is disclosed. The thermal stack is formed by machining a block of reticulated vitreous carbon into the required shape of the thermal stack. In a second embodiment, a micro-thermoacoustic device is disclosed which includes a thermal stack made of a piece of porous material such as reticulated vitreous carbon. In another embodiment, a heat exchanger is disclosed which is formed of a block of heat conductive open cell foam material.

A thermoacoustic device is described having a thermal stack made from a piece of porous material which provides a desirable ratio of thermoacoustic area to viscous area, which has a low resistance to flow, which minimizes acoustic streaming and which has a high specific heat and low thermal conductivity. The thermal stack is easy and cheap to form and it can be formed in small sizes. Specifically, in one embodiment, a thermal stack which is formed by the natural structure of a porous material such as reticulated vitreous carbon is disclosed. The thermal stack is formed by machining a block of reticulated vitreous carbon into the required shape of the thermal stack. In a second embodiment, a micro-thermoacoustic device is disclosed which includes a thermal stack made of a piece of porous material such as reticulated vitreous carbon. In another embodiment, a heat exchanger is disclosed which is formed of a block of heat conductive open cell foam material. 13 figs.

reported before. Through improving the refrigerant performance of heat and mass transfer in the adsorbent bed, the refrigeration cycle has been advanced from the aspect of utilization of the thermal energy from low-temperature level resources. In addition...

SAVE WITH HYBRID REFRIGERATION Cheng-Wen (Wayne) Chung, P.E. Fluor Engineers, Inc. Irvine, California ABSTRACT Two level demand makes it possible to use two systems for refrigeration and save energy and money. An example of this type... of refrigeration, consisting of an ammonia absorption refrigeration (AAR) unit and a mechanical compression refrigera tion (MCR) unit, is presented in this article. This paper will briefly describe process configur ation, advantages and utility consumption...

Food Service Â» Install a heat pump Food Service Â» Install a heat pump water heaterand reduce water heating energy up to 70% using the commercialheat pump water heater specificat Activities Technology Solutions Teams Lighting & Electrical Space Conditioning Plug & Process Loads Food Service Refrigeration Laboratories Energy Management & Information Systems Public Sector Teams Market Solutions Teams Install a heat pump water heaterand reduce water heating energy up to 70% using the commercialheat pump water heater specification The Food Service team developed a CommercialHeat Pump Water Heater Specification that can be used to reduce water heating energy by 70%. An older, electric resistance water heater (operated in a building with a hot water demand of 500 gallons a day) can cost more than $3,500 each year

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Determining the coefficient of performance of a vapour compression refrigeration cycle. Apparatus Figure 1, a condenser, an evaporator and an expansion valve. The compressor unit shown in Fig. 2 comprises the liquid to vapor. The system has an expansion valve which is a float valve. Schematic of the expansion

The derivation of general performance benchmarks is important in the design of highly optimized heat engines and refrigerators. To obtain them, one may model phenomenologically the leading sources of irreversibility ending up with results which are model-independent, but limited in scope. Alternatively, one can take a simple physical system realizing a thermodynamic cycle and assess its optimal operation from a complete microscopic description. We follow this approach in order to derive the coefficient of performance at maximum cooling rate for \\textit{any} endoreversible quantum refrigerator. At striking variance with the \\textit{universality} of the optimal efficiency of heat engines, we find that the cooling performance at maximum power is crucially determined by the details of the specific system-bath interaction mechanism. A closed analytical benchmark is found for endoreversible refrigerators weakly coupled to unstructured bosonic heat baths: an ubiquitous case study in quantum thermodynamics.

Combined heat and power fuel cell systems (CHP-FCSs) provide consistent electrical power and hot water with greater efficiency and lower emissions than alternative sources. These systems can be used either as baseload, grid-connected, or as off-the-grid power sources. This report presents a business case for CHP-FCSs in the range of 5 to 50 kWe. Systems in this power range are considered micro-CHP-FCS. For this particular business case, commercial applications rather than residential or industrial are targeted. To understand the benefits of implementing a micro-CHP-FCS, the characteristics that determine their competitive advantage must first be identified. Locations with high electricity prices and low natural gas prices are ideal locations for micro-CHP-FCSs. Fortunately, these high spark spread locations are generally in the northeastern area of the United States and California where government incentives are already in place to offset the current high cost of the micro-CHP-FCSs. As a result of the inherently high efficiency of a fuel cell and their ability to use the waste heat that is generated as a CHP, they have higher efficiency. This results in lower fuel costs than comparable alternative small-scale power systems (e.g., microturbines and reciprocating engines). A variety of markets should consider micro-CHP-FCSs including those that require both heat and baseload electricity throughout the year. In addition, the reliable power of micro-CHP-FCSs could be beneficial to markets where electrical outages are especially frequent or costly. Greenhouse gas emission levels from micro-CHP-FCSs are 69 percent lower, and the human health costs are 99.9 percent lower, than those attributed to conventional coal-fired power plants. As a result, FCSs can allow a company to advertise as environmentally conscious and provide a bottom-line sales advantage. As a new technology in the early stages of adoption, micro-CHP-FCSs are currently more expensive than alternative technologies. As the technology gains a foothold in its target markets and demand increases, the costs will decline in response to improved manufacturing efficiencies, similar to trends seen with other technologies. Transparency Market Research forecasts suggest that the CHP-FCS market will grow at a compound annual growth rate of greater than 27 percent over the next 5 years. These production level increases, coupled with the expected low price of natural gas, indicate the economic payback period will move to less than 5 years over the course of the next 5 years. To better understand the benefits of micro-CHP-FCSs, The U.S. Department of Energy worked with ClearEdge Power to install fifteen 5-kWe fuel cells in the commercial markets of California and Oregon. Pacific Northwest National Laboratory is evaluating these systems in terms of economics, operations, and their environmental impact in real-world applications. As expected, the economic analysis has indicated that the high capital cost of the micro-CHP-FCSs results in a longer payback period than typically is acceptable for all but early-adopter market segments. However, a payback period of less than 3 years may be expected as increased production brings system cost down, and CHP incentives are maintained or improved.

Refrigerators use more energy than any other kitchen appliance -- an unsurprising fact considering that refrigerators operate 24 hours a day, 365 days a year to keep food at a safe temperature. In many low-income households, refrigerators eat up more than half the electricity consumed in one year. And if the refrigerator in a family's home is functioning poorly, the cost to the consumer can be enormous. Discovering whether an existing refrigerator is operating inefficiently enough to warrant replacing it is an extremely difficult task for a resident who sees only a monthly electric bill. Only by knowing the approximate usage of the existing unit can anyone tell whether it would pay to buy a new, energy-efficient refrigerator. The savings from replacing older refrigerators can be substantial, and collecting the data needed to determine when refrigerators should be replaced is easier and less costly than one might think. In both Chicago and New York City, replacing existing units cut refrigerator electricity usage by more than 50%. Monitoring to develop an average usage for the existing stock of refrigerators is a task that can be completed by maintenance staff in a reasonably short time -- and identifying poorly performing units that should be immediately replaced can take just two hours of monitoring.

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included, though some may be added at a later date. The database identifies sources of specific information on refrigerants. It addresses lubricants including alkylbenzene, polyalkylene glycol, polyolester, and other synthetics as well as mineral oils. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits. Incomplete citations or abstracts are provided for some documents. They are included to accelerate availability of the information and will be completed or replaced in future updates. Citations in this report are divided into the following topics: thermophysical properties; materials compatibility; lubricants and tribology; application data; safety; test and analysis methods; impacts; regulatory actions; substitute refrigerants; identification; absorption and adsorption; research programs; and miscellaneous documents. Information is also presented on ordering instructions for the computerized version.

Thermodynamics is a branch of science blessed by an unparalleled combination of generality of scope and formal simplicity. Based on few natural assumptions together with the four laws, it sets the boundaries between possible and impossible in macroscopic aggregates of matter. This triggered groundbreaking achievements in physics, chemistry and engineering over the last two centuries. Close analogues of those fundamental laws are now being established at the level of individual quantum systems, thus placing limits on the operation of quantum-mechanical devices. Here we study quantum absorption refrigerators, which are driven by heat rather than external work. We establish thermodynamic performance bounds for these machines and investigate their quantum origin. We also show how those bounds may be pushed beyond what is classically achievable, by suitably tailoring the environmental fluctuations via quantum reservoir engineering techniques. Such superefficient quantum-enhanced cooling realises a promising step towards the technological exploitation of autonomous quantum refrigerators.

The Salida Geothermal Prospect (Poncha Hot Springs) was evaluated for industrial and commercial direct heat applications at Salida, Colorado, which is located approximately five miles east of Poncha Hot Springs. Chaffee Geothermal, Ltd., holds the geothermal leases on the prospect and the right-of-way for the main pipeline to Salida. The Poncha Hot Springs are located at the intersection of two major structural trends, immediately between the Upper Arkansas graben and the Sangre de Cristo uplift. Prominent east-west faulting occurs at the actual location of the hot springs. Preliminary exploration indicates that 1600 gpm of geothermal fluid as hot as 250/sup 0/F is likely to be found at around 1500 feet in depth. The prospective existing endusers were estimated to require 5.02 x 10/sup 10/ Btu per year, but the total annual amount of geothermal energy available for existing and future endusers is 28.14 x 10/sup 10/ Btu. The engineering design for the study assumed that the 1600 gpm would be fully utilized. Some users would be cascaded and the spent fluid would be cooled and discharged to nearby rivers. The economic analysis assumes that two separate businesses, the energy producer and the energy distributor, are participants in the geothermal project. The producer would be an existing limited partnership, with Chaffee Geothermal, Ltd. as one of the partners; the distributor would be a new Colorado corporation without additional income sources. Economic evaluations were performed in full for four cases: the Base Case and three alternate scenarios. Alternate 1 assumes a three-year delay in realizing full production relative to the Base Case; Alternate 2 assumes that the geothermal reservoir is of a higher quality than is assumed for the Base Case; and Alternate 3 assumes a lower quality reservoir. 11 refs., 34 figs., 40 tabs.

Lubricating oils suitable for use in refrigeration equipment in admixture with fluorinated hydrocarbon refrigerants are produced by solvent extraction of naphthenic lubricating oil base stocks, cooling the resulting extract mixture, optionally with the addition of a solvent modifier, to form a secondary raffinate and a secondary extract, and recovering a dewaxed oil fraction of lowered pour point from the secondary raffinate as a refrigeration oil product. The process of the invention obviates the need for a separate dewaxing operation, such as dewaxing with urea, as conventionally employed for the production of refrigeration oils.

Information is presented about the energy costs of operating refrigerators and refrigerator-freezers and includes the type of refrigerator or refrigerator-freezer, the fresh food volume, the freezer volume, the total volume, and the yearly energy cost. The directory lists all currently marketed electric refrigerators and refrigerator-freezers that have Energy Guide labels. The Federal Trade Commission requires manufacturers who distribute refrigerators and refrigerator-freezers to attach Energy Guide labels to appliances manufactured on or after May 19, 1980. The data have been measured by manufacturers and/or their agents according to US Government standard test procedures.

The development of condensing heat exchanger systems is studied. In the work reported here, the focus is on the corrosion resistance of materials to condensate produced by gas-fired heating equipment, and the characterization of the spatial variation of condensation corrosivity in condensing heat exchangers.

The Refrigerant Database consolidates and facilitates access to information to assist industry in developing equipment using alternative refrigerants. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air- conditioning and refrigeration equipment. The complete documents are not included, though some may be added at a later date. The database identifies sources of specific information on R-32, R-123, R-124, R- 125, R-134a, R-141b, R142b, R-143a, R-152a, R-290 (propane), R-717 (ammonia), ethers, and others as well as azeotropic and zeotropic blends of these fluids. It addresses polyalkylene glycol (PAG), ester, and other lubricants. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits.

Sample records for heat commercial refrigeration from the National Library of Energy Beta (NLEBeta)

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DOE Proposes Higher Efficiency Standards for Refrigerators DOE Proposes Higher Efficiency Standards for Refrigerators DOE Proposes Higher Efficiency Standards for Refrigerators September 28, 2010 - 12:00am Addthis WASHINGTON, DC - U.S. Energy Secretary Steven Chu today announced the release of a new proposed energy efficiency standard for residential refrigerators, refrigerator-freezers, and freezers. The standard, as proposed, could save consumers as much as $18.6 billion over thirty years. The Obama Administration has made efficiency standards a major priority as a way to save energy and money for American families and businesses. Since January 2009, the Department of Energy has finalized new efficiency standards for more than twenty household and commercial products, which will cumulatively save consumers between $250 billion and

This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors have carried out a range of tasks directed toward the construction and testing of a proof-of-principle optical refrigerator prototype. They procured and tested new cooling elements that are at the heart of an optical refrigerator. The cooling element absorbs pump radiation and then fluoresces with nearly unity quantum efficiency. They constructed and tested a cooling chamber with low thermal emissivity walls that reduces the parasitic heating.

The Foundation House, planned to house half a dozen nonprofit foundations, will be constructed on 64th Street just east of Central Park in Manhattan, New York. It is in a Landmark District and designed by the architectural firm of Henry George Greene, AIA of Scarsdale, NY (project architect, David Wasserman). The 20,000-square foot building of five floors above ground and two below, will illustrate how energy-savings technology and environmentally sensitive construction methods can be economical. The heating and cooling system, including refrigeration requirements for the freezers and refrigerators in the commercial kitchen, will be provided by geothermal heat pumps using standing column wells. The facility is the first building on the island of Manhattan to feature geothermal heating and cooling. The mechanical system has been the assistance of Carl Orio`s firm of Water & Energy Systems corporation of Atkinson, New Hampshire. The two 1550-foot standing column wells were drilled by John Barnes of Flushing, NY.

??In the past two decades the refrigeration, air-conditioning and heat pump industries began the conversion from chlorofluorocarbon (CFC) refrigerants to hydrochlorofluorocarbons (HCFCs) and to natural (more)

Significant developments have occurred in hydrofluorocarbon (HFC) and the application of ammonia and hydrocarbons as refrigerant working fluids since the original TEWI (Total Equivalent Warming Impact) report in 1991. System operating and performance data on alternative refrigerants and refrigeration technologies justify and updated evaluation of these new alternative refrigerants and competing technologies in well-characterized applications. Analytical and experimental results are used to show quantitative comparisons between HFCS, HFC blends, hydrocarbons, and ammonia, used as refrigerants. An objective evaluation is presented for commercial and near commercial non-CFC refrigerants/blowing agents and alternative refrigeration technologies. This information is needed for objective and quantitative decisions on policies addressing greenhouse gas emissions from refrigeration and air conditioning equipment. The evaluation assesses the energy use and global warming impacts of refrigeration and air conditioning technologies that could be commercialized during the phase out of HCFCS. Quantitative comparison TEWI for two application areas are presented. Opportunities for significant reductions in TEWI are seen with currently known refrigerants through improved maintenance and servicing practices and improved product designs.

Supermarket refrigeration capabilities were first added to EnergyPlus in 2004. At that time, it was possible to model a direct expansion (DX) rack system with multiple refrigerated cases. The basic simulation software handles all the building energy uses, typically on a 5 to 10 minute time step throughout the period of interest. The original refrigeration module included the ability to model the sensible and latent interactions between the refrigerated cases and the building HVAC system, along with some basic heat recovery capabilities. Over the last few years, the refrigeration module has been expanded to handle more complex systems, such as secondary loops, shared condensers, cascade condensers, subcoolers, and walk-in coolers exchanging energy with multiple conditioned zones.

The U.S. Department of Energy (DOE) is publishing this final rule to implement provisions in the Energy Conservation and Production Act (ECPA) that require DOE to update the baseline Federal energy efficiency performance standards for the construction of new Federal commercial and multi-family high-rise residential buildings. This rule updates the baseline Federal commercial standard to the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) Standard 90.1-2013.

ABSTRACT The purpose of this paper is to present: 1) a description of a solar/geothermal heating and cooling system that has been in successful operation in a commercial office building for over five years; and 2) to present technical and cost operational results that indicate a total annual energy consumption of approximately 25,000 Btu/sq ft/ year. The paper includes a general description of the three-story multi-tenant office building located in Burlington, Massachusetts, its energy efficient design features, its active solar space heating and hot water system, its solar/geothermal heat pump back-up heating system and its geothermal cooling system. A description of the solar/geothermal system is presented including the liquid flat plate collectors, storage tanks, heat exchangers, heat pump, heat transfer fluid, control system, operational modes and the energy monitoring system. KEYWORDS Solar space heating; geothermal heating; geothermal cooling; solar domestic hot water; energy monitoring and control.

What is disclosed is a heat exchanger-accumulator for vaporizing a refrigerant or the like, characterized by an upright pressure vessel having a top, bottom and side walls; an inlet conduit eccentrically and sealingly penetrating through the top; a tubular overflow chamber disposed within the vessel and sealingly connected with the bottom so as to define an annular outer volumetric chamber for receiving refrigerant; a heat transfer coil disposed in the outer volumetric chamber for vaporizing the liquid refrigerant that accumulates there; the heat transfer coil defining a passageway for circulating an externally supplied heat exchange fluid; transferring heat efficiently from the fluid; and freely allowing vaporized refrigerant to escape upwardly from the liquid refrigerant; and a refrigerant discharge conduit penetrating sealingly through the top and traversing substantially the length of the pressurized vessel downwardly and upwardly such that its inlet is near the top of the pressurized vessel so as to provide a means for transporting refrigerant vapor from the vessel. The refrigerant discharge conduit has metering orifices, or passageways, penetrating laterally through its walls near the bottom, communicating respectively interiorly and exteriorly of the overflow chamber for controllably carrying small amounts of liquid refrigerant and oil to the effluent stream of refrigerant gas.

Sample records for heat commercial refrigeration from the National Library of Energy Beta (NLEBeta)

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and sorbic acid at a level of 0.3 perceiit prevented hearlng completely in all feed ingredients tested. Smaller amounts of the inhibitors only delayed heating. Propion- ic acid and propionic anhydride, each at a level of 0.1 percent, prevented heating.... Sodium propionate was not effective as a fungistatic agent at a level of 0.6 percent. Propionamide and propionanalide alsc -xrnra not effective at a level of 0.1 percent which was the maximum level tested. Short-chain fatty acids-butyric, valeric...

In 2007 we developed a prototype refrigerator with a small turbo?expander to provide adequate cooling power (2 kW at 70 K) for HTS (High Temperature Superconductor) power machines. The reverse?Brayton cycle with neon gas as a working fluid was adopted in the refrigerator. The prototype refrigerator does not have enough COP (Coefficient of Performance) for practical HTS applications and the purpose of this study is to research the information required for designing a new neon refrigerator with improved performance. We take the same refrigeration cycle and working fluid as the prototype one adopted but a lower process pressure of 1 MPa/0.5 MPa is chosen instead of 2 MPa/1 MPa. The lower process pressure is required by the turbo?compressor design and the refrigeration process is analyzed by using a newly developed process simulator. Also a heat?exchanger configuration is studied to make the refrigerator size small. The new refrigerator will have a cooling power of 2.5 kW at 65 K and a COP of 0.06 at 80 K.

A dilution refrigerator is required for 50mK detector operation of CDMS (Cryogenic Dark Matter Search). Besides shielding the dilution refrigerator itself, the liquid nitrogen shield and liquid helium bath in the refrigerator cool the detector cryostat heat shields and cool electronics, resulting in significant external heat loads at 80K and at 4K. An Oxford Instruments Kelvinox 400 has served this role for ten years but required daily transfers of liquid nitrogen and liquid helium. Complicating the cryogen supply is the location 800 meters below ground in an RF shielded, class 10000 clean room at Soudan, MN. Nitrogen and helium re-liquefiers using cryocoolers were installed outside the clean room and continuously condense room temperature gas and return the liquids to the dilution refrigerator through a transfer line. This paper will describe the design, installation, controls and performance of liquefaction systems.

This report summarizes a preliminary design study to explore the plausibility of using pulse tube refrigeration to cool instruments in a hot down-hole environment. The original motivation was to maintain Dave Reagor`s high-temperature superconducting electronics at 75 K, but the study has evolved to include three target design criteria: cooling at 30 C in a 300 C environment, cooling at 75 K in a 50 C environment, cooling at both 75 K and 30 C in a 250 C environment. These specific temperatures were chosen arbitrarily, as representative of what is possible. The primary goals are low cost, reliability, and small package diameter. Pulse-tube refrigeration is a rapidly growing sub-field of cryogenic refrigeration. The pulse tube refrigerator has recently become the simplest, cheapest, most rugged and reliable low-power cryocooler. The authors expect this technology will be applicable downhole because of the ratio of hot to cold temperatures (in absolute units, such as Kelvin) of interest in deep drilling is comparable to the ratios routinely achieved with cryogenic pulse-tube refrigerators.

The task of the project was to build a solar heating system for a large community pool. Racks for the sixty collectors were constructed of redwood as described in the section on carpentry work. The plumbing section details the ease of putting together the collectors as well as the difficulty of hooking up the pipe to the pumps and inline filters. An automatic controller unit turns the pumps on and off depending on the availability of sunlight. After two years of work, the system is operable, but the pool cover purchased in the first year may be more effective than the entire solar heating system. Optimal solar efficiency may not be practical. The details of this finding are discussed in the section on conclusions, pitfalls, and recommendations.

A heat pump has a refrigerant loop, a compressor in fluid communication with the refrigerant loop, at least one indoor heat exchanger in fluid communication with the refrigerant loop, and at least one outdoor heat exchanger in fluid communication with the refrigerant loop. The at least one outdoor heat exchanger has a phase change material in thermal communication with the refrigerant loop and in fluid communication with an outdoor environment. Other systems, devices, and methods are described.

A solar concentrating trough device has been constructed for further application of solar heating and power system or solar refrigeration. A model for both evacuated tube and copper tube heated by solar trough co...

Utility-sponsored refrigerator and freezer pick-up programs have removed almost 900,000 inefficient appliances from the North American electric grid to date. While the CFC-12 refrigerant from the discarded appliances is typically removed and recycled, in all but a few programs the CFC-11 in the foam insulation is not. About a quarter-billion pounds of CFC-11 are banked in refrigerator foam in the United States. Release of this ``bank`` of CFC, combined with that from foam insulation used in buildings, will be the largest source of future emissions if preventive measures are not taken. Methods exist to recover the CFC for reuse or to destroy it by incineration. The task of recycling or destroying the CFCs and other materials from millions of refrigerators is a daunting challenge, but one in which utilities can play a leadership role. E Source believes that utilities can profitably serve as the catalyst for public-private partnerships that deliver comprehensive refrigerator recycling. Rather than treating such efforts solely as a DSM resource acquisition, utilities could position these programs as a multifaceted service delivery that offers convenient appliance removal for homeowners, a solid waste minimization service for landfills, a source of recycled materials for industry, and a CFC recovery and/or disposal service in support of the HVAC industry and society`s atmospheric protection goals and laws. Financial mechanisms could be developed through these public-private enterprises to ensure that utilities are compensated for the extra cost of fully recycling refrigerators, including the foam CFC.

This paper presents energy and life cycle climate performance (LCCP) analyses of a variety of supermarket refrigeration systems to identify designs that exhibit low environmental impact and high energy efficiency. EnergyPlus was used to model refrigeration systems in a variety of climate zones across the United States. The refrigeration systems that were modeled include the traditional multiplex DX system, cascade systems with secondary loops and the transcritical CO2 system. Furthermore, a variety of refrigerants were investigated, including R-32, R-134a, R-404A, R-1234yf, R-717, and R-744. LCCP analysis was used to determine the direct and indirect carbon dioxide emissions resulting from the operation of the various refrigeration systems over their lifetimes. Our analysis revealed that high-efficiency supermarket refrigeration systems may result in up to 44% less energy consumption and 78% reduced carbon dioxide emissions compared to the baseline multiplex DX system. This is an encouraging result for legislators, policy makers and supermarket owners to select low emission, high-efficiency commercialrefrigeration system designs for future retrofit and new projects.

-1209(h) Office Hours: M-F 1-2p.m. Text: Heating, Ventilating, and Air Conditioning - Analysis and Design. -- Refrigeration and heating, ventilating and air-conditioning (HVAC) for comfort and industrial applications of the fundamentals of Heating, Ventilating, Air Conditioning, and Refrigeration as they relate to human comfort

. 1875" OD exchanger Qu ID copper cap Fig. 6. Assembled view of 3He - He dilution refrigerator. 26 The joint thru the tubing wall and the joining of the two sizes of capillary were silver soldered (35/ silver content). A 0. 250" OD tube... the inert atmosphere inside the refrigerator. After removal from the nitrogen atmosphere the graphite support, was 'attached to the still and mixing chamber using Stycast 2850 GT with catalyst g9 ). The mass of the graphite 26 support 1s 11. 62 grams...

Due to industry concerns about the successful employment of hydrofluorocarbon-immiscible hydrocarbon oils in refrigeration systems, enhanced naphthenic refrigeration oils have been developed. These products have been designed to be more dispersible with hydrofluorocarbon (HFC) refrigerants, such as R-134a, in order to facilitate lubricant return to the compressor and to ensure proper energy efficiency of the system. Bench tests and system performance evaluations indicate the feasibility of these oils for use in household refrigeration applications. Results of these evaluations are compared with those obtained with polyol esters and typical naphthenic mineral oils employed in chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) refrigeration applications.

Thermal insulation of the pulse tube in a pulse-tube refrigerator is maintained by optimally varying the radius of the pulse tube to suppress convective heat loss from mass flux streaming in the pulse tube. A simple cone with an optimum taper angle will often provide sufficient improvement. Alternatively, the pulse tube radius r as a function of axial position x can be shaped with r(x) such that streaming is optimally suppressed at each x.

A protocol was developed to define calorimeter operating pressures for nonazeotropic refrigerant mixtures (NARMs) which corresponded with the saturated evaporator and condenser temperatures commonly used for pure refrigerants. Compressor calorimeter results were obtained using this equivalent-mean-temperature (EMT) approach and a generally applied Association of Home Appliance Manufacturers (AHAM) procedure at conditions characteristic of a domestic refrigerator-freezer application. Tests with R-12 and two NARMs indicate that compressor volumetric and isentropic efficiencies are nearly the same for refrigerants with similar capacities and pressure ratios. The liquid-line temperature conditions specified in the AHAM calorimeter rating procedure for refrigerator-freezer compressors were found to preferentially derate NARM performance relative to R-12. Conversion of calorimeter data taken with a fixed liquid-line temperature to a uniform minimal level of condenser subcooling is recommended as a fairer procedure when NARMs are involved. Compressor energy-efficiency-ratio (EER) and capacity data measured as a result of the EMT approach were compared to system performance calculated using an equivalent-heat-exchanger-loading (EHXL) protocol based on a Lorenz-Meutzner (L-M) refrigerator-freezer modeling program. The EHXL protocol was used to transform the calorimeter results into a more relevant representation of potential L-M cycle performance. The EMT method used to set up the calorimeter tests and the AHAM liquid-line conditions combined to significantly understate the cycle potential of NARMs relative to that predicted at the more appropriate EHXL conditions. Compressor conditions representative of larger heat exchanger sizes were also found to give a smaller L-M cycle advantage relative to R-12.

The study describes the development of heat-activated industrial refrigeration systems using ammoniated complex compound sorption media. The focus was on single-stage cycles for low temperature (+20 F and below) refrigeration. Compared to vapor compression refrigeration, these cycles have the advantages of lower operating energy costs, reduction of peak electrical demand and associated demand charges, and reduced maintenance costs due to replacement of the compressor with solid-state sorbers. In many cases, particularly for refrigeration at -40 F and below, complex compound sorption cycles also have the potential for lower first cost than conventional electrically driven refrigeration systems. Technical issues addressed included the following: economic optimization of sorber design, demonstration of cyclic stability of the sorption reactions, construction material compatibility, and reactor scale-up. Sorption reactions for refrigeration at -40 F, and -70 F were demonstrated. Optimum heat exchanger configuration, complex compound loading, and cycle time were determined.

The experimental results of a compression refrigerator with an integrated solution circuit, a so-called compression-absorption cycle, are presented. The compression refrigerator operates with ammonia (NH3) as refrigerant. The cycle is improved by two-stage throttling of the condensate and an absorption circuit which replaces the economizer compressor. The absorption circuit operates on the working pair ammonia/water (NH3/H2O). It is driven by superheat of the compressor without additional heat input from an external source. By this means the benefit of two-stage throttling, namely a reduction in compression work or an increase in refrigeration capacity, can be doubled. In the experiments an improvement of up to 9% in the efficiency of the NH3-refrigeration cycle has been attained. Compared to a simple compression refrigerator, the presented compression-absorption cycle has a payback time of only several months. Compared to a conventional economizer refrigeration cycle, the payback can be expected within the range of several months to about four years.

MARKET Table 1 below presents information on the manufacturing industries that are intensive in process cooling and refrigeration (PC&R) energy consumption as monitored by the US Energy Information Administration (EIA). The information in Table 1... Expansion (DX), Pumped Liquid Overfeed, Flooded shell and tube and Plate heat exchangers. Evaporators in the refrigerated space can contribute as much as 10 to 15% of the energy consumption in an industrial refrigeration system and therefore...

Chemical heat pump cools as well as heats ... Innovative heat pump uses methanol refrigerant, calcium chloride absorber to use and store solar energy for heating, air conditioning, hot water ... Though the EIC heat pump is similar in concept to other chemical heat pumps now being used or developed, it does offer a number of innovations, not the least of which are its novel refrigerant (methanol) and absorption medium (calcium chloride). ...

Sample records for heat commercial refrigeration from the National Library of Energy Beta (NLEBeta)

Note: This page contains sample records for the topic "heat commercial refrigeration" from the National Library of EnergyBeta (NLEBeta).
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and refrigerators. The analyses provided are based on the skematic diagram shown below. The system is a working the ideal, theoretical limit, Stot =0. Refrigerator A refrigerator is also a heat pump. However, with a refrigerator we are interested in how much energy we can pump out of the low temperature reservoir (the

The Southern California Edison Company (SCE) and the California Energy Commission (CEC) have contracted with the Energy Analysis Program of the Applied Science Division at the Lawrence Berkeley Laboratory (LBL) to develop an integrated set of commercial sector load shapes (LS) and energy utilization indices (EUI) for use in forecasting electricity demand. The objectives of this project are to conduct detailed analyses of SCE data on commercial building characteristics, energy use, and whole-building load shapes; and in conjunction with other data, to develop, test, and apply an integrated approach for the estimation of end-use LSs and EUIs. The project represents one of the first attempts to combine simulation-based, prototypical building analyses with direct reconciliation to measured hourly load data. The project examined electricity and gas use for nine building types, including large offices, small offices, large retails, small retails, food stores, sitdown restaurants, fastfood restaurants, refrigerated warehouses, and non-refrigerated warehouses. For each building type, nine end uses were examined, including cooling, heating, ventilation, indoor lighting, outdoor lighting, miscellaneous equipment, water heating, cooking, and refrigeration. For the HVAC end uses (cooling, ventilation, and heating), separate analyses were performed for three climate zones: coastal, inland, and desert.

The application field of the free-piston Stirling Cooler, Model 100A of Global Cooling BV in the refrigeration has been studied. The cooling effectiveness of the free-piston Stirling Cooler which means small capacity with better efficiency, large range of temperature and capacity modulated operation is of much use to cool a space insulated well. One practicable application is suggested here, in which FPSC and secondary heat transfer fluid are used to the single temperature refrigerator (60 liter) instead of conventional vapor compression machines. In the freezer operation at {minus}20 C inside cabinet, the steady-state test results show 25% improvement in energy consumption over original one. The application of free-piston Stirling Cooler to a freezer at lower temperature shows great potentials also.

A review is presented of our program to construct an efficient solid state refrigerator based on thermionic emission of electrons over periodic barriers in the solid. The experimental program is to construct a simple device with one barrier layer using a three layers: metal-semiconductor-metal. The theoretical program is doing calculations to determine: (i) the optimal layer thickness, and (ii) the thermal conductivity.

For the Central American Health Clinic Project initiated in 1986, Sandia National Laboratories and the Florida Solar Energy Center recognized the need for a test and evaluation program for vaccine refrigeration systems. At the Florida Solar Energy Center, side-by-side testing of three photovoltaic powered vaccine refrigerators began in 1987. The testing was expanded in 1988 to include a kerosene absorption refrigerator. This report presents observations, conclusions, and recommendations derived from testing the four vaccine refrigeration systems. Information is presented pertaining to the refrigerators, photovoltaic arrays, battery subsystems, charge controllers, and user requirements. This report should be of interest to designers, manufacturers, installers, and users of photovoltaic-powered vaccine refrigeration systems and components.

The rate of temperature decrease of a cooled quantum bath is studied as its temperature is reduced to absolute zero. The third law of thermodynamics is then quantified dynamically by evaluating the characteristic exponent ? of the cooling process dT(t)dt??T? when approaching absolute zero, T?0. A continuous model of a quantum refrigerator is employed consisting of a working medium composed either by two coupled harmonic oscillators or two coupled two-level systems. The refrigerator is a nonlinear device merging three currents from three heat baths: a cold bath to be cooled, a hot bath as an entropy sink, and a driving bath which is the source of cooling power. A heat-driven refrigerator (absorption refrigerator) is compared to a power-driven refrigerator. When optimized, both cases lead to the same exponent ?, showing a lack of dependence on the form of the working medium and the characteristics of the drivers. The characteristic exponent is therefore determined by the properties of the cold reservoir and its interaction with the system. Two generic heat bath models are considered: a bath composed of harmonic oscillators and a bath composed of ideal Bose/Fermi gas. The restrictions on the interaction Hamiltonian imposed by the third law are discussed. In the Appendices, the theory of periodically driven open systems and its implication for thermodynamics are outlined.

The LSST Camera has a higher cryogenic heat load than previous CCD telescope cameras due to its large size (634 mm diameter focal plane, 3.2 Giga pixels) and its close coupled front-end electronics operating at low temperature inside the cryostat. Various refrigeration technologies are considered for this telescope/camera environment. MMR-Technologys Mixed Refrigerant technology was chosen. A collaboration with that company was started in 2009. The system, based on a cluster of Joule-Thomson refrigerators running a special blend of mixed refrigerants is described. Both the advantages and problems of applying this technology to telescope camera refrigeration are discussed. Test results from a prototype refrigerator running in a realistic telescope configuration are reported. Current and future stages of the development program are described. (auth)

As a result of the Montreal Protocol that limits the production of ozone-depleting refrigerants, manufacturers are searching for alternatives to replace the R12 that is presently used in residential refrigerator-freezers. Before an alternative can be selected, several issues must be resolved. Among these are energy impacts, system compatibility, cost, and availability. In an effort to determine the energy impacts of some of the alternatives, energy consumption tests were performed in accordance with section 8 of the Association of Home Appliance Manufacturers (AHAM) standard for household refrigerators and household freezers. The results are presented for an 18 cubic foot (0.51 cubic meter), top-mount refrigerator-freezer with a static condenser using the following refrigerants: R12, R500, R12/Dimethyl-ether (DME), R22/R142b, and R134a. Conclusions from the AHAM test are that R500 and R12 /DME have a reduced energy consumption relative to R12 when replaced in the test unit with no modifications to the refrigeration system. Run times were slightly lower than R12 for both refrigerants indicating a higher capacity. While the R134a and R22/R142b results were less promising refrigeration system, such as a different capillary tube or compressor, may improve their performance. 12 refs., 2 figs., 3 tabs.

Method and apparatus to extract heat by transferring heat from hot compressed refrigerant to a coolant, such as water, without exceeding preselected temperatures in the coolant and avoiding boiling in a water system by removing the coolant from direct or indirect contact with the hot refrigerant.

This article discusses how a simple, new technology threw the best-laid plans of the chemical and refrigerator industries into disarray-and provided a new perspective on how future environmental agreements can be reached. In recent years, a series of massive business mergers has mesmerized the industrial world. However in the early 1990s a German environmentalist, triggered global reprocussions in the wake of the mandate to phase out the use of ozone depleting substances. The economic and political background of this is explained in detail.

A heat absorption method for an absorption chiller is described comprising: (a) providing a first absorption system circuit for operation within a first temperature range; (b) providing a second absorption system circuit for operation within a second temperature range which has a lower maximum temperature than the first temperature range; (c) heat exchanging refrigerant and absorber solution from the first circuit condenser and absorber with absorption solution from the generator of the second circuit; and (d) the evaporator of the first circuit and the evaporator of the second circuit both being disposed in thermal communication with an external heat load to withdraw heat from the heat load.

This paper describes the progress made in demonstrating a Malone Cycle Refrigerator/Freezer. The Malone cycle is similar to the Stirling cycle but uses a supercritical fluid in place of real gas. In the approach, solid-metal diaphragms are used to seal and sweep the working volumes against the high working fluid pressures required in Malone cycle machines. This feature eliminates the friction and leakage that accounted for nearly half the losses in the best piston-defined Malone cycle machines built to date. The authors successfully built a Malone cycle refrigerator that: (1) used CO{sub 2} as the working fluid, (2) operated at pressures up to 19.3 Mpa (2,800 psi), (3) achieved a cold end metal temperatures of {minus}29 C ({minus}20 F), and (4) produced over 400 Watts of cooling at near ambient temperatures. The critical diaphragm components operated flawlessly throughout characterization and performance testing, supporting the conclusion of high reliability based on analysis of fatigue date and actual strain measurements.

A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation. The refrigeration system is compact with a self-contained pumping system and heaters for operation of the system. A mixing chamber contains .sup.3 He and .sup.4 He liquids which are precooled by a coupled container containing .sup.3 He liquid, enabling the phase separation of a .sup.3 He rich liquid phase from a dilute .sup.3 He-.sup.4 He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the .sup.3 He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute .sup.3 He-.sup.4 He liquid phase.

An indoor unit for an electric heat pump is provided in modular form including a refrigeration module, an air mover module, and a resistance heat package module, the refrigeration module including all of the indoor refrigerant circuit components including the compressor in a space adjacent the heat exchanger, the modules being adapted to be connected to air flow communication in several different ways as shown to accommodate placement of the unit in various orientations. 9 figs.

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This patent describes a diffusion cloud chamber isothermally heatsunk refrigerator which comprises: a heatsink consisting of two phases of a saturated substance existing in thermodynamic equilibrium at constant pressure and therefore at constant temperature, contained in a reservoir; a means of pressure damping to maintain constant pressure, as the ratio of the two phases present changes and introduces volumetric changes in the substance; a cooling member which transfer heat from vapor in contact with the cooling member surface to the ''cold side'' of a Peltier thermoelectric element with which the cooling member is in thermal contact; a Peltier thermoelectric element which removes the heat supplied by the cooling member from its ''cold side'' and pumps it to the ''hot side'' when driven by an electric current; and a means of transferring heat from the ''hot side'' of the Peltier thermoelectric element to the two-phase isothermal substance in the reservoir.

CommercialCommercial Jump to: navigation, search Click to return to AEO2011 page AEO2011 Data From AEO2011 report . Market Trends The AEO2011 Reference case shows minimal change in commercial energy use per capita between 2009 and 2035 (Figure 62). While growth in commercial floorspace (1.2 percent per year) is faster than growth in population (0.9 percent per year), energy use per capita remains relatively steady due to efficiency improvements in equipment and building shells. Efficiency standards and the addition of more efficient technologies account for a large share of the improvement in the efficiency of end-use services, notably in space cooling, refrigeration, and lighting.[1] Issues in Focus In 2009, the residential and commercial buildings sectors used 19.6

Response Opportunities in Industrial Refrigerated Warehouses in Response Opportunities in Industrial Refrigerated Warehouses in California Title Demand Response Opportunities in Industrial Refrigerated Warehouses in California Publication Type Conference Paper LBNL Report Number LBNL-4837E Year of Publication 2011 Authors Goli, Sasank, Aimee T. McKane, and Daniel Olsen Conference Name 2011 ACEEE Summer Study on Energy Efficiency in Industry Date Published 08/2011 Conference Location Niagara Falls, NY Keywords market sectors, openadr, refrigerated warehouses Abstract Industrial refrigerated warehouses that implemented energy efficiency measures and have centralized control systems can be excellent candidates for Automated Demand Response (Auto-DR) due to equipment synergies, and receptivity of facility managers to strategies that control energy costs without disrupting facility operations. Auto-DR utilizes OpenADR protocol for continuous and open communication signals over internet, allowing facilities to automate their Demand Response (DR). Refrigerated warehouses were selected for research because: They have significant power demand especially during utility peak periods; most processes are not sensitive to short-term (2-4 hours) lower power and DR activities are often not disruptive to facility operations; the number of processes is limited and well understood; and past experience with some DR strategies successful in commercial buildings may apply to refrigerated warehouses. This paper presents an overview of the potential for load sheds and shifts from baseline electricity use in response to DR events, along with physical configurations and operating characteristics of refrigerated warehouses. Analysis of data from two case studies and nine facilities in Pacific Gas and Electric territory, confirmed the DR abilities inherent to refrigerated warehouses but showed significant variation across facilities. Further, while load from California's refrigerated warehouses in 2008 was 360 MW with estimated DR potential of 45-90 MW, actual achieved was much less due to low participation. Efforts to overcome barriers to increased participation may include, improved marketing and recruitment of potential DR sites, better alignment and emphasis on financial benefits of participation, and use of Auto-DR to increase consistency of participation.

The report gives results of an investigation of the significance of heat leakage through gaskets in household refrigerator/freezers, explores different design features, and suggests further study if necessary. The report gives results of an extensive literature review, interviews with refrigerator/freezer and gasket manufacturers, and some engineering analysis. (NOTE: Home refrigerators are the largest consumers of electricity among household appliances and are consuming an estimated 8% of the total electricity used in the U.S. Recent studies show that gasket area heat leakage may account for as much as 21% of the total thermal load.)

Method of making an active magnetic refrigerant represented by Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4 alloy for 0.ltoreq.x.ltoreq.1.0 comprising placing amounts of the commercially pure Gd, Si, and Ge charge components in a crucible, heating the charge contents under subambient pressure to a melting temperature of the alloy for a time sufficient to homogenize the alloy and oxidize carbon with oxygen present in the Gd charge component to reduce carbon, rapidly solidifying the alloy in the crucible, and heat treating the solidified alloy at a temperature below the melting temperature for a time effective to homogenize a microstructure of the solidified material, and then cooling sufficiently fast to prevent the eutectoid decomposition and improve magnetocaloric and/or the magnetostrictive and/or the magnetoresistive properties thereof.

Commercial household refrigerators use simple, cost-effective, temperature controllers to obtain acceptable control. A manually adjusted airflow damper regulates the freezer compartment temperature while a thermostat controls operation of the compressor and evaporator fan to regulate refrigerator compartment temperature. Dual compartment temperature control can be achieved with automatic airflow dampers that function independently of the compressor and evaporator fan thermostat, resulting in improved temperature control quality and energy consumption. Under dual control, freezer temperature is controlled by the thermostat while the damper controls refrigerator temperature by regulating airflow circulation. A simulation model is presented that analyzes a household refrigerator configured with a conventional thermostat and both manual and automatic dampers. The model provides a new paradigm for investigating refrigerator systems and temperature control performance relative to the extensive verification testing that is typically done by manufacturers. The effects of each type of control and damper configuration are compared with respect to energy usage, control quality, and ambient temperature shift criteria. The results indicate that the appropriate control configuration can have significant effects and can improve plant performance.

Experimental and theoretical investigations were presented dealing with three phase direct-contact heat transfer by evaporation of refrigerant drops in an immiscible liquid. Refrigerant R12 was used as the dispersed phase, while water and brine were the immiscible continuous phase. A numerical solution is presented to predict the formation rate of gas hydrates in test column. The solution provided an acceptable agreement when compared with experimental results. The gas hydrate growth rate increased with time. It increased with increasing dispersed phase flow rate. The presence of surface-active sodium chloride in water had a strong inhibiting effect on the gas hydrate formation rate. (author)

In recent years thermoelectricity sees rapidly increasing usages in applications like portable refrigerators beverage coolers electronic component coolers etc. when used as Thermoelectric Cooler (TEC) and Thermoelectric Generators (TEG) which make use of the Seebeck effect in semiconductors for the direct conversion of heat into electrical energy and is of particular interest for systems of highest reliability or for waste heat recovery. In this work we examine the performance of commercially available TEC and TEG. A prototype TEC?refrigerator has been designed modeled and constructed for in?car applications. Additionally a TEG was made in order to measure the gained power and efficiency. Furthermore a TEG module was tested on a small size car (Toyota Starlet 1300 cc) in order to measure the gained power and efficiency for various engine loads. With the use of a modeling approach we evaluated the thermal contact resistances and their influence on the final device efficiency.

kJ/kg. a. Calculate the heat of vaporisation of the R-40 at 30Â°C and -20Â°C, and calculate with methylchloride (CH3Cl, R-40) as refrigerant. The evaporator operates at Te = -20 Â°C and exchanges heat-1), closing the cycle. The following data is given for these states: T Â°C p bar h kJ/kg s kJ/(kgÂ·K) 1 -20 1

A technique for producing a cold environment in a refrigerant system in which input fluid from a compressor at a first temperature is introduced into an input channel of the system and is pre-cooled to a second temperature for supply to one of at least two stages of the system, and to a third temperature for supply to another stage thereof. The temperatures at such stages are reduced to fourth and fifth temperatures below the second and third temperatures, respectively. Fluid at the fourth temperature from the one stage is returned through the input channel to the compressor and fluid at the fifth temperature from the other stage is returned to the compressor through an output channel so that pre-cooling of the input fluid to the one stage occurs by regenerative cooling and counterflow cooling and pre-cooling of the input fluid to the other stage occurs primarily by counterflow cooling.

A quantum absorption refrigerator driven by noise is studied with the purpose of determining the limitations of cooling to absolute zero. The model consists of a working medium coupled simultaneously to hot, cold and noise baths. Explicit expressions for the cooling power are obtained for Gaussian and Poisson white noise. The quantum model is consistent with the first and second laws of thermodynamics. The third law is quantified, the cooling power J_c vanishes as J_c proportional to T_c^{alpha}, when T_c approach 0, where alpha =d+1 for dissipation by emission and absorption of quanta described by a linear coupling to a thermal bosonic field, where d is the dimension of the bath.

The experimental testing on residential refrigerator/freezers (R/Fs) is summarized in this paper. R/F testing focused on two areas: alternative refrigerants and equipment configurations. The refrigerants evaluated consisted of single components, azeotropes, and zeotropes derived from hydrofluorocarbons (HFCs) and hydrocarbons (HCs). These refrigerants were evaluated in conventional and unconventional R/F designs. Major and minor design modifications were studied. Minor modifications consisted of various capillary tube lengths, door insulations, and compressors, while major modifications included two-evaporator and two-cycle R/F systems. Results obtained from testing the two-cycle system will be discussed in a later paper. This paper presents the experimental results of alternative technologies evaluated as replacements for ozone depleting chemicals.

As a result of the Montreal Protocol (UNEP 1987) that limits the production of ozone-depleting refrigerants, manufacturers are searching for alternatives to replace the R12 that is presently used in residential refrigerator-freezers. Before an alternative can be selected, several issues must resolved. Among these are energy impacts, system compatibility, cost, and availability, In an effort to determine the energy impacts of some of the alternatives, energy consumption tests were performed in accordance with section 8 of the Association of Home Appliance Manufacturers (AHAM) standard for household refrigerators and household freezers (AHAM 1985). The results are presented for an 18 ft{sup 3} (0.51 m{sup 3}), top mount refrigerators-freezer with a static condenser using the following refrigerants: R 12, R500, R12/dimethylether (DME), R22/R142b, and R134a. Conclusions from the AHAM test are that R500 and R12/DME have a reduced energy consumption relative to R12 when replaced in the test unit with no modifications to the refrigeration system. Run times were slightly lower than R12 for both refrigerants, indicating a higher capacity. While the R134a and R22/R142b results were less promising (6.8% and 8.5% higher energy consumption, respectively), changes to the refrigeration system, such as a different capillary tube or compressor, may improve their performance. It is noted that the test results are only an initial step in determining a replacement for R12.

A thermoacoustic refrigerator and a thermoacoustic prime mover, due to its simple structure, would serve as very desirable systems because thermoacoustic prime movers can be driven with the waste heat such as an exhaust gas from engines, and with heat from the nature such as sunlight and a geothermal heat. The thermoacoustic refrigerator and the thermoacoustic prime mover combined would serve as a perfect cooling system without moving parts, CFC's and HFC's. Thus this Thermoacoustic-driven Thermoacoustic Refrigerator will replace the previous paper compression refrigeration system. The authors set up the thermoacoustic refrigerator and thermoacoustic prime mover to investigate the fundamental characteristics. On the refrigerator tests, dimensions of the stack are varied as a parameter of experiments. As a result, influences of the stack configuration on the performance are confirmed, so the design method for the optimum dimension to attain the large temperature difference can be indicated. About the prime mover tests, fundamental characteristics of stack dimensions is checked. The way to improve the thermal efficiency of the prime mover is mentioned in terms of the operating condition. Numerical calculations about the refrigerator are made which is based on the enthalpy flow model by Radebaugh. The result of calculations has a good agreement in quality with the experimental results, so the propriety of this model is confirmed.

by operating the central heating system to preheat the dwelling sufficiently to keep the air temperature above 70Â°F for the duration of the test, or by using supplemental electric resistance heating devices on for the refrigerant charge test. This preheating is best accomplished by the central heating system, but a plug

The work in this report was conducted by the Analytic Studies Division (ASD) of the National Renewable Energy Laboratory (NREL) for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy, Office of Building Technologies. This case study describes the development and implementation of the Super Efficient Refrigerator Program (SERP), which awarded $30 million to the refrigerator manufacturer that developed and commercialized a refrigerator that exceeded 1993 federal efficiency standards by at least 25%. The program was funded by 24 public and private utilities. As the first Golden Carrot program to be implemented in the United States, SERP was studied as an example for future `market-pull` efforts.

A magnetic refrigeration apparatus includes first and second steady state magnets, each having a field of substantially equal strength and opposite polarity, first and second bodies made of magnetocaloric material disposed respectively in the influence of the fields of the first and second steady state magnets, and a pulsed magnet, concentric with the first and second steady state magnets, and having a field which cycles between the fields of the first and second steady state magnets, thereby cyclically magnetizing and demagnetizing and thus heating and cooling the first and second bodies. Heat exchange apparatus of suitable design can be used to expose a working fluid to the first and second bodies of magnetocaloric material. A controller is provided to synchronize the flow of working fluid with the changing states of magnetization of the first and second bodies. 2 figs.

Sample records for heat commercial refrigeration from the National Library of Energy Beta (NLEBeta)

Note: This page contains sample records for the topic "heat commercial refrigeration" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
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CBECS Public Use Data CBECS Public Use Data CBECS Public Use Data Public Use Files: yellow indicator arrow 2003 CBECS | yellow indicator arrow 1999 CBECS | yellow indicator arrow 1995 CBECS | yellow indicator arrow 1992 CBECS The Public Use Files are microdata files that contain more than 5,000 records, representing commercial buildings from the 50 States and the District of Columbia. Each record corresponds to a single responding, in-scope sampled building and contains information for that building about the building size, year constructed, types of energy used, energy-using equipment, conservation features, energy consumption and expenditures, and the amount of energy used for nine end uses: space heating, cooling, ventilation, lighting, water heating, cooking, refrigeration, office equipment, and other end uses.

Industrial refrigerated warehouses that implemented energy efficiency measures and have centralized control systems can be excellent candidates for Automated Demand Response (Auto-DR) due to equipment synergies, and receptivity of facility managers to strategies that control energy costs without disrupting facility operations. Auto-DR utilizes OpenADR protocol for continuous and open communication signals over internet, allowing facilities to automate their Demand Response (DR). Refrigerated warehouses were selected for research because: They have significant power demand especially during utility peak periods; most processes are not sensitive to short-term (2-4 hours) lower power and DR activities are often not disruptive to facility operations; the number of processes is limited and well understood; and past experience with some DR strategies successful in commercial buildings may apply to refrigerated warehouses. This paper presents an overview of the potential for load sheds and shifts from baseline electricity use in response to DR events, along with physical configurations and operating characteristics of refrigerated warehouses. Analysis of data from two case studies and nine facilities in Pacific Gas and Electric territory, confirmed the DR abilities inherent to refrigerated warehouses but showed significant variation across facilities. Further, while load from California's refrigerated warehouses in 2008 was 360 MW with estimated DR potential of 45-90 MW, actual achieved was much less due to low participation. Efforts to overcome barriers to increased participation may include, improved marketing and recruitment of potential DR sites, better alignment and emphasis on financial benefits of participation, and use of Auto-DR to increase consistency of participation.

Project objectives: To install and monitor an innovative WaterFurnace geothermal system that is technologically advanced and evolving; To generate hot water heating from a heat pump that uses non-ozone depleting refrigerant CO2. To demonstrate the energy efficiency of this system ground source heat pump system.

A team led by GE Global Research developed new magnetic refrigerant materials needed to enhance the commercialization potential of residential appliances such as refrigerators and air conditioners based on the magnetocaloric effect (a nonvapor compression cooling cycle). The new magnetic refrigerant materials have potentially better performance at lower cost than existing materials, increasing technology readiness level. The performance target of the new magnetocaloric material was to reduce the magnetic field needed to achieve 4 °C adiabatic temperature change from 1.5 Tesla to 0.75 Tesla. Such a reduction in field minimizes the cost of the magnet assembly needed for a magnetic refrigerator. Such a reduction in magnet assembly cost is crucial to achieving commercialization of magnetic refrigerator technology. This project was organized as an iterative alloy development effort with a parallel material modeling task being performed at George Washington University. Four families of novel magnetocaloric alloys were identified, screened, and assessed for their performance potential in a magnetic refrigeration cycle. Compositions from three of the alloy families were manufactured into regenerator components. At the beginning of the project a previously studied magnetocaloric alloy was selected for manufacturing into the first regenerator component. Each of the regenerators was tested in magnetic refrigerator prototypes at a subcontractor at at GE Appliances. The property targets for operating temperature range, operating temperature control, magnetic field sensitivity, and corrosion resistance were met. The targets for adiabatic temperature change and thermal hysteresis were not met. The high thermal hysteresis also prevented the regenerator components from displaying measurable cooling power when tested in prototype magnetic refrigerators. Magnetic refrigerant alloy compositions that were predicted to have low hysteresis were not attainable with conventional alloy processing methods. Preliminary experiments with rapid solidification methods showed a path towards attaining low hysteresis compositions should this alloy development effort be continued.

This report documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Commercial Sector Demand Module. The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated through the synthesis and scenario development based on these components. The NEMS Commercial Sector Demand Module is a simulation tool based upon economic and engineering relationships that models commercial sector energy demands at the nine Census Division level of detail for eleven distinct categories of commercial buildings. Commercial equipment selections are performed for the major fuels of electricity, natural gas, and distillate fuel, for the major services of space heating, space cooling, water heating, ventilation, cooking, refrigeration, and lighting. The algorithm also models demand for the minor fuels of residual oil, liquefied petroleum gas, steam coal, motor gasoline, and kerosene, the renewable fuel sources of wood and municipal solid waste, and the minor services of office equipment. Section 2 of this report discusses the purpose of the model, detailing its objectives, primary input and output quantities, and the relationship of the Commercial Module to the other modules of the NEMS system. Section 3 of the report describes the rationale behind the model design, providing insights into further assumptions utilized in the model development process to this point. Section 3 also reviews alternative commercial sector modeling methodologies drawn from existing literature, providing a comparison to the chosen approach. Section 4 details the model structure, using graphics and text to illustrate model flows and key computations.

A triple effect absorption refrigeration system is provided with a double-condenser coupling and a parallel or series circuit for feeding the refrigerant-containing absorbent solution through the high, medium, and low temperature generators utilized in the triple-effect system. The high temperature condenser receiving vaporous refrigerant from the high temperature generator is double coupled to both the medium temperature generator and the low temperature generator to enhance the internal recovery of heat within the system and thereby increase the thermal efficiency thereof.

A control system for thermoelectric refrigerators is disclosed. The thermoelectric refrigerator includes at least one thermoelectric element that undergoes a first order change at a predetermined critical temperature. The element functions as a thermoelectric refrigerator element above the critical temperature, but discontinuously ceases to function as a thermoelectric refrigerator element below the critical temperature. One example of such an arrangement includes thermoelectric refrigerator elements which are superconductors. The transition temperature of one of the superconductor elements is selected as the temperature control point of the refrigerator. When the refrigerator attempts to cool below the point, the metals become superconductors losing their ability to perform as a thermoelectric refrigerator. An extremely accurate, first-order control is realized.

DOE ordered International Refrigeration Products to pay an $8,000 civil penalty after finding International Refrigeration had failed to certify that certain room air conditioners comply with the applicable energy conservation standard.

This report examines energy intensities in commercial buildings for nine end uses: space heating, cooling, ventilation, lighting, water heating, cooking, refrigeration, office equipment, and other. The objective of this analysis was to increase understanding of how energy is used in commercial buildings and to identify targets for greater energy efficiency which could moderate future growth in demand. The source of data for the analysis is the 1989 Commercial Buildings Energy Consumption survey (CBECS), which collected detailed data on energy-related characteristics and energy consumption for a nationally representative sample of approximately 6,000 commercial buildings. The analysis used 1989 CBECS data because the 1992 CBECS data were not yet available at the time the study was initiated. The CBECS data were fed into the Facility Energy Decision Screening (FEDS) system, a building energy simulation program developed by the US Department of Energy`s Pacific Northwest Laboratory, to derive engineering estimates of end-use consumption for each building in the sample. The FEDS estimates were then statistically adjusted to match the total energy consumption for each building. This is the Energy Information Administration`s (EIA) first report on energy end-use consumption in commercial buildings. This report is part of an effort to address customer requests for more information on how energy is used in buildings, which was an overall theme of the 1992 user needs study. The end-use data presented in this report were not available for publication in Commercial Buildings Energy Consumption and Expenditures 1989 (DOE/EIA-0318(89), Washington, DC, April 1992). However, subsequent reports on end-use energy consumption will be part of the Commercial Buildings Energy Consumption and Expenditures series, beginning with a 1992 data report to be published in early 1995.

The disclosure is directed to a wheel-type magnetic refrigerator capable of cooling over a large temperature range. Ferromagnetic or paramagnetic porous materials are layered circumferentially according to their Curie temperature. The innermost layer has the lowest Curie temperature and the outermost layer has the highest Curie temperature. The wheel is rotated through a magnetic field perpendicular to the axis of the wheel and parallel to its direction of rotation. A fluid is pumped through portions of the layers using inner and outer manifolds to achieve refrigeration of a thermal load. 7 figs.

The helium refrigerator was cooled down and operated for the third time since its installation. D-Zero's 2 Tesla superconducting solenoid was cooled down and operated for its second time since its installation into the D-Zero detector. This engineering note summarizes the cryogenic aspects of the test run and performance measurements made. The main purpose of this run was to do field mapping of the solenoid with different combinations of field polarity on the Solenoid and CF iron magnets. This was accomplished. A second purpose was to test the lower field joint repair that was done in January 1999. This field joint had a measurable voltage drop across the soldered bus splice. The repair was an undoing of the joint, extensive cleaning of the bus, and then welding the splice. The repair was successful, no voltage drop was measured and the magnet behaved nicely. A parasitic purpose was to get some operating time on the refrigerator, measure the refrigeration performance, and measure the heat leak in the VLPC lines mounted on the detector platform. Refrigerator performance was spot checked, and was found to be 60 watts (10%) less than generic operating curves. At this level of performance, the operating margin for the full solenoid and VLPC system will be 75 watts (15%) which is somewhat uncomfortable from an operational stand point. The VLPC lines were operated and heat leak numbers of around 40 watts was measured for each pipe section including the supply u-tubes to the detector, the bayonet can, valve box on the platform and the piping back to the refrigerator valve box. Another purpose of the test run was to test the compatibility of other detector components with the new central magnetic field environment. I do not know the results of these tests.

An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

Sample records for heat commercial refrigeration from the National Library of Energy Beta (NLEBeta)

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energy and off-peak electric resistance heating. Estimated energy and first cost savings, as compared with an all-electric VAV HVAC system, are: 30 to 50% in ductwork size and cost; 30% in fan energy; 25% in air handling equipment; 20 to 40% in utility...

The mass flow characteristics of flashing Refrigerant-22 from a small vessel were investigated. A flash boiling apparatus was designed and built. It was modeled after the flashing process encountered by the accumulator of air-source heat pump...

A heat pump system includes, in an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant: a compressor; an interior heat exchanger; an exterior heat exchanger; an accumulator; and means for heating the accumulator in order to defrost the exterior heat exchanger. 2 figs.

The mechanism of adsorption refrigeration is shown in Fig 1. The adsorption system is sealed, when adsorbent filled in adsorber is heated, adsorbate adsorbed in adsorbent gains energy. When molecule movement rate of adsorbate is enough to overcome affinity... between adsorbate and adsorbent, adsorbate will be desorbed. When sub-pressure of the system gradually increasing reaches the value of saturation steam pressure corresponding to environmental temperature, adsorbate desorbed from adsorbent...

Magnetic refrigeration was investigated as an efficient, environmentally friendly, flexible alternative to conventional residential vapor compression central air conditioning systems. Finite element analysis (FEA) models of advanced geometry active magnetic regenerator (AMR) beds were developed to minimize bed size and thus magnet mass by optimizing geometry for fluid flow and heat transfer and other losses. Conventional and magnetocaloric material (MCM) regenerator fabrication and assembly techniques were developed and advanced geometry passive regenerators were built and tested. A subscale engineering prototype (SEP) magnetic air conditioner was designed, constructed and tested. A model of the AMR cycle, combined with knowledge from passive regenerator experiments and FEA results, was used to design the regenerator beds. A 1.5 Tesla permanent magnet assembly was designed using FEA and the bed structure and plenum design was extensively optimized using FEA. The SEP is a flexible magnetic refrigeration platform, with individually instrumented beds and high flow rate and high frequency capability, although the current advanced regenerator geometry beds do not meet performance expectations, probably due to manufacturing and assembly tolerances. A model of the AMR cycle was used to optimize the design of a 3 ton capacity magnetic air conditioner, and the system design was iterated to minimize external parasitic losses such as heat exchanger pressure drop and fan power. The manufacturing cost for the entire air conditioning system was estimated, and while the estimated SEER efficiency is high, the magnetic air conditioning system is not cost competitive as currently configured. The 3 ton study results indicate that there are other applications where magnetic refrigeration is anticipated to have cost advantages over conventional systems, especially applications where magnetic refrigeration, through the use of its aqueous heat transfer fluid, could eliminate intermediate heat exchangers or oil distribution issues found in traditional vapor compression systems.

A prototype magnetically-coupled Stirling engine-driven heat pump module has been designed and fabricated by Sunpower, Inc. under sponsorship of the US Department of Energy and the Oak Ridge National Laboratory (ORNL). Preliminary testing indicates that the magnetic coupling is an effective means for transmitting power from a free-piston Stirling engine to a refrigerant compressor. Compared with other power transmission concepts, the magnetic coupling has relatively low cost, and will help make commercial development of Stirling-driven heat pumps more likely in the future.

A prototype magnetically-coupled Stirling engine-driven heat pump module has been designed and fabricated by Sunpower, Inc. under sponsorship of the US Department of Energy and the Oak Ridge National Laboratory (ORNL). Preliminary testing indicates that the magnetic coupling is an effective means for transmitting power from a free-piston Stirling engine to a refrigerant compressor. Compared with other power transmission concepts, the magnetic coupling has relatively low cost, and will help make commercial development of Stirling-driven heat pumps more likely in the future.

in refrigeration and heat pump systems, HVAC, porous media development/characterization, transport phenomena of compact and lightweight heat exchangers for evaporator and condenser; v) Development of heatdriven adsorption chillers tailored to service vehicles; vi) Development and implementation of thermal energy

The high ambient temperature of the Canadian Standards Association (CSA) and the AHAM/DOE Refrigerator-Freezer Energy Consumption Standards is intended to compensate for the lack of door openings and other heat loads. Recently published results by Meier and Jansky (1993) indicate labeled consumption overpredicting typical field consumption by 15%. In-house field studies on conventional models showed labeled consumption overpredicting by about 22%. The Refrigerator-Freezer Technology Assessment (RFTA) test was developed to more accurately predict field consumption. This test has ambient temperature and humidity, door openings, and condensation control set at levels intended to typify Canadian household conditions. It also assesses consumption at exactly defined compartment rating temperatures. Ten conventional and energy-efficient production models were laboratory tested. The RFTA results were about 30% lower than labeled. Similarly, the four innovative refrigerator-freezer models, when field tested, also had an average of 30% lower consumption than labeled. Thus, the results of the limited testing suggest that the RFTA test may be a more accurate predictor of field use. Further testing with a larger sample is recommended. Experimental results also indicated that some innovative models could save up to 50% of the energy consumption compared with similar conventional units. The technologies that contributed to this performance included dual compressors, more efficient compressors and fan motors, off-state refrigerant control valve, fuzzy logic control, and thicker insulation. The larger savings were on limited production models, for which additional production engineering is required for full marketability.

Simulation analyses suggest that a multispeed compressor could increase steady-state operating efficiency by 4% to 14%. An additional 0.5% to 4% energy savings might be obtained from the reduction in the cycling frequency of the refrigerator. Several aspects of the robustness of the capillary tube-suction line heat exchanger design for the two-speed compressor system were also examined with the simulation model. It was shown that a system optimized for low-speed operation, when operating at the high speed, could have as much capacity as the original base case high-speed system. A relatively simple control strategy was proposed, one that requires measurement of on-cycle time and one or two compartment air temperatures. The effects of varying the speed of the evaporator or condenser fans at both compressor speeds were examined over a range of ambient temperatures. One energy-saving scenario was identified: decreasing the condenser fan speed for refrigerators operating at low ambient temperatures. By affecting the distribution of refrigerant change throughout the system, the decrease in condenser fan speed reduces the superheat in the evaporator and increases the overall UA of the evaporator. The resulting increase in evaporator capacity more than offsets the decrease in condenser UA and the energy use of the refrigerator is decreased.

FEMP provides acquisition guidance across a variety of product categories, including residential refrigerators, which are an ENERGY STAR®-qualified product category. Federal laws and executive orders mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law.

)" #12;1. Introduction Brazed aluminium heat exchangers are composed of flat tubes on the refrigerant exchangers with round tube, such as charge reduction and higher heat transfer coefficient. But, according are thus not suitable to small-channel heat exchangers. As a consequence, the refrigerant distribution

Optical refrigeration has been demonstrated by several groups of researchers, but the cooling elements have not been thermally linked to realistic heat loads in ways that achieve the desired temperatures. The ideal thermal link will have minimal surface area, provide complete optical isolation for the load, and possess high thermal conductivity. We have designed thermal links that minimize the absorption of fluoresced photons by the heat load using multiple mirrors and geometric shapes including a hemisphere, a kinked waveguide, and a tapered waveguide. While total link performance is dependent on additional factors, we have observed net transmission of photons with the tapered link as low as 0.04%. Our optical tests have been performed with a surrogate source that operates at 625 nm and mimics the angular distribution of light emitted from the cooling element of the Los Alamos solid state optical refrigerator. We have confirmed the optical performance of our various link geometries with computer simulations using CODE V optical modeling software. In addition we have used the thermal modeling tool in COMSOL MULTIPHYSICS to investigate other heating factors that affect the thermal performance of the optical refrigerator. Assuming an ideal cooling element and a nonabsorptive dielectric trapping mirror, the three dominant heating factors are (1) absorption of fluoresced photons transmitted through the thermal link, (2) blackbody radiation from the surrounding environment, and (3) conductive heat transfer through mechanical supports. Modeling results show that a 1 cm{sup 3} load can be chilled to 107 K with a 100 W pump laser. We have used the simulated steady-state cooling temperatures of the heat load to compare link designs and system configurations.

Improving energy efficiency in water heating applications is important to the nation's energy strategies. Water heating in residential and commercial buildings accounts for about 10% of U.S. buildings energy consumption. Heat pump water heating (HPWH) technology is a significant breakthrough in energy efficiency, as an alternative to electric resistance water heating. Heat pump technology has shown acceptable payback period with proper incentives and successful market penetration is emerging. However, current HPWH require the use of refrigerants with high Global Warming Potential (GWP). Furthermore, current system designs depend greatly on the backup resistance heaters when the ambient temperature is below freezing or when hot water demand increases. Finally, the performance of current HPWH technology degrades greatly as the water set point temperature exceeds 330 K. This paper presents the potential for carbon dioxide, CO2, as a natural, environmentally benign alternative refrigerant for HPWH technology. In this paper, we first describe the system design, implications and opportunities of operating a transcritical cycle. Next, a prototype CO2 HPWH design featuring flexible component evaluation capability is described. The experimental setup and results are then illustrated followed by a brief discussion on the measured system performance. The paper ends with conclusions and recommendations for the development of CO2 heat pump water heating technology suitable for the U.S. market.

1334E-2009 1334E-2009 Effect of Heat and Electricity Storage and Reliability on Microgrid Viability: A Study of Commercial Buildings in California and New York States Michael Stadler, Chris Marnay, Afzal Siddiqui, Judy Lai, Brian Coffey, and Hirohisa Aki Environmental Energy Technologies Division Revised March 2009 http://eetd.lbl.gov/EA/EMP/emp-pubs.html The work described in this paper was funded by the Office of Electricity Delivery and Energy Reliability, Renewable and Distributed Systems Integration Program in the U.S. Department of Energy under Contract No. DE-AC02- 05CH11231. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Disclaimer This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct

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We present a non-contact spectroscopic teclmique for the measurement of laser-induced temperature changes in solids. Two-band differential luminescence thermometry (TBDLT) achieves a sensitivity of {approx}7 mK and enables precise measurement of the net quantum efficiency of optical refrigerator materials. TBDLT detects internal temperature changes by decoupling surface and bulk heating effects via time-resolved luminescence spectroscopy. Several Yb{sup 3+}-doped fluorozirconate (ZBLANI) glasses fabricated from precursors of varying purity and by different processes are analyzed in detail. A net quantum efficiency of 97.39% at 238 K (at a pump wavelength of 1020.5 nm) is found for a ZBLANI:1%Yb{sup 3+} laser-cooling sample produced from metal fluoride precursors that were purified by chelate-assisted solvent extraction and dried in hydrofluoric gas. In comparison, a ZBLANI:1%Yb{sup 3+} sample produced from commercial-grade metal fluoride precursors showed pronounced laser-induced heating that is indicative of a substantially higher impurity concentration. TBDLT enables rapid and sensitive benchmarking of laser-cooling materials and provides critical feedback to the development and optimization of high-performance optical cryocooler materials.

The Supermarket Refrigeration System project was structured to investigate and develop a new, highly energy-efficient supermarket refrigeration system which features unequal, parallel compressors, microprocessor suction pressure control, and floating head pressure control. Energy savings are achieved because such a system is better able to match compressor capacity with the required refrigeration load. For this same reason, the unequal, parallel compressor system can operate at the lowest possible condenser pressure. The combined effect of highest possible suction pressure and lowest possible condensing pressure substantially increases the energy efficiency ratio (EER) of the refrigeration system. The test conditions included winter and spring ambient temperatures ranging from 8/sup 0/ to 70/sup 0/F, refrigerants R-12 and R-502 with corresponding evaporator temperatures of 20/sup 0/ and -20/sup 0/F, respectively, and variable refrigeration loads between 100,000 and 170,000 Btu/hr. Heat reclaim tests were performed with R-12 only. For the three sets of tests performed, R-12, R-12 with heat reclaim, and R-502, the highest system EER was achieved when the unequal, parallel compressor system was operated with microprocessor control and floating head control.

This patent describes a heat absorption method for an absorption chiller. It comprises: providing a firs absorption system circuit for operation within a first temperature range, providing a second absorption system circuit for operation within a second temperature range; heat exchanging refrigerant and absorber solution; thermal communication with an external heat load. This patent describes a heat absorption apparatus for use as an absorption chiller. It includes: a first absorption system circuit for operation within a first temperature range; a second absorption system circuit for operation within a second temperature range which has a lower maximum temperature relative to the first temperature range; the first circuit having generator means, condenser means, evaporator means, and absorber means operatively connected together; the second circuit having generator means condenser means, evaporator means, and absorber means operative connected together; and the first circuit condenser means and the first circuit absorber means being in heat exchange communication with the second circuit generator means.

Codes and Standards Codes and Standards Photo of two inspectors looking at a clipboard on a commercial building site with the steel frame of a commercial building in the background. Local code officials enforce building energy codes. Credit: iStockphoto Once an energy-efficient technology or practice is widely available in the market, it can become the baseline of performance through building energy codes and equipment standards. The Building Technologies Office (BTO) provides support to states and local governments as they adopt and monitor commercial building code as well as builders working to meet and exceed code. BTO also develops test procedures and minimum efficiency standards for commercial equipment. Building Energy Codes DOE encourages using new technologies and better building practices to improve energy efficiency. Mandating building energy efficiency by including it in state and local codes is an effective strategy for achieving that goal. The Building Energy Codes Program works with the International Code Council (ICC), American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), Illuminating Engineering Society of North America (IESNA), American Institute of Architects (AIA), the building industry, and state and local officials to develop and promote more stringent and easy-to-understand building energy codes and to assess potential code barriers to new energy-efficient technologies.

The capacity of a LNG liquefaction unit has been increased by upgrading the refrigeration system, without making changes to the main heat exchanger (MHE). It is interesting, that after all modifications were completed, a higher refrigerant circulation alone could not increase LNG production. However, by optimizing the refrigerant component ratio, the UA of the MHE increased and LNG production improved. This technical evaluation will provide recommendations and show how the evaluation of the internal temperature profile helped optimize the MHE operating conditions.

The HFC Supermarket Refrigeration Demonstration tested and evaluated HFC refrigerants in a new Shop `n Save supermarket in Glens Falls, New York. This project included laboratory testing of HFC refrigerants for medium- and low-temperature application, the design of a supermarket refrigeration system to accommodate the new refrigerants, installation, start-up, and field monitoring.

This report presents an evaluation of supermarket refrigeration involving the use of conventional and multiplex compressor systems. Computer simulations of these systems were performed for six representative sites. The performance predictions generated in this fashion were tabulated to allow hand calculation of electric costs for any prevailing electric rate schedule. A methodology was also developed to allow economic assessment of the conventional and multiplex systems and of various enhancements employed with the multiplex system. The results of the evaluation showed the multiplex refrigeration system produced a reasonable payback for all sites examined, depending upon the enhancements employed. System features that had the greatest impact on payback were heat reclaim, hot gas defrost, and floating head pressure. 25 figs., 28 tabs.

Design features for a new range of helium liquefiers and refrigerators with capacities ranging from 30 to 280 l/h of liquid helium (LHe) and 100 to 900 Watt respectively. The latest He cold box development shows an increased efficiency due to improved turbine and heat exchanger design. Other benefits of the new design include short cool-down times and a very compact design which offers better flexibility and process control. The modularity of the system was designed in order to cover a wide range of applications like sophisticated shield cooling at different temperature levels or simultaneous operation modes for He liquefaction and refrigeration purposes. The presentation will highlight the individual improvements in the design.

A hermetic refrigeration compressor includes a suction muffler formed from two pieces of plastic material mounted on the cylinder housing. One piece is cylindrical in shape with an end wall having an aperture for receiving a suction tube connected to the cylinder head. The other piece fits over and covers the other end of the cylindrical piece, and includes a flaring entrance horn which extends toward the return line on the sidewall of the compressor shell. 5 figs.

Abstract Solar sorption refrigeration technologies are regarded as a promising way to meet the growing refrigeration needs in Africa, for thermal comfort, foods and crops, vaccines and medicines conservation. Sorption technologies projects and studies have been reported in Africa since the late 1970s. This paper describes the most representative reported research activities and projects in various African climatic conditions. An emphasis is put on demonstrative plants involving absorption, adsorption or desiccant cooling applications. From this overview, it appears that a lot of achievements have been made, though applications are mainly focused on small-size cold boxes for foods and vaccines preservation; no direct building air conditioning based on adsorption or absorption has been reported. Mediterranean countries seems to offer the best weather conditions for solar sorption refrigeration applications and plenty of related activities could be identified in these countries. A more adequate design for each of other climatic zones in Africa may then be relevant. As anywhere, the high cost of these technologies remains the main the biggest brake to their diffusion in Africa.

, and rocket engines are heat engines. So are steam engines and turbines #12;2 refrigerator Device that uses by steam turbines. Steam turbines, jet engines and rocket engines use a Brayton cycle #12;4 Steam turbines1 Heat engine Device that transforms heat into work. It requires two energy reservoirs at different

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Abstract Natural gas is widely use in many industries as fuel and also as raw material. Although gas pipelines present less transportation losses they become impracticable when distances are too long or when demands are highly variable. The liquefaction of natural gas is then necessary to allow its transportation in great volumes, with little loss of material. This also enables its storage in a more stable way. Natural gas consumption is continuously growing worldwide and consequently, the number of exporter terminals (liquefaction industries) and importer terminals (regasification plants) will increase. The natural gas liquefaction process is based on a sequence of refrigeration cycles, which need to work in an optimized way. The exergetic analysis is a very useful thermodynamic tool to evaluate the efficiency of these cycles. This work aims at an exergetic analysis of a multistage cascade refrigeration cycle applied to a natural gas liquefaction process. Firstly, the process was simulated using commercial software and the results obtained from the simulations were validated with literature data, showing a good agreement. After that, different operational conditions, according to a complete factorial design of experiments, were studied, in order to verify the influence of pressure in six specific points of the cycle. The response variable analyzed is the rate of total exergy destroyed in the cycle. The results showed a new set of operational condition to the refrigeration cycle in which the destroyed exergy rate was reduced by approximately 48% in comparison with literature data.

Requirements for Determining Refrigerant Charge Residential Air Conditioning Measures Improved Refrigerant Charge Purpose Component packages require in some climate zones that split system air refrigerant charge. For the performance method, the proposed design is modeled with less efficiency

Ammonia refrigeration systems are widely used in industry. Demand of these systems is expected to increase due to the advantages of ammonia as refrigerant and because ammonia is considered a green refrigerant. Therefore, it is important to evaluate...

For helium refrigerators using liquid nitrogen (LN) pre-cooling it is not uncommon for the ambient helium refrigeration return stream(s) exiting the cold box to be significantly colder and for the cycle to use more nitrogen than estimated by the process studies. Often there is an emphasis on the length of 300 to 80-K helium-nitrogen heat exchangers to ensure the exiting nitrogen is as close to ambient as possible. However, it is really the size and flow distribution of the 300 to 80-K helium-helium heat exchangers which are the dominate influence of the nitrogen consumption. As such, an analysis was done to identify and quantify the sensitivity the key parameters in the refrigerator LN pre-cooler section affecting the LN consumption.

This paper presents the current results of the development of a Modelica library for CO2-refrigeration systems based on the free Modelica library ThermoFluid. The development of the library is carried out in a research project of Airbus Deutschland and the TUHH and is focused on the aim to obtain a library for detailed numerical investigations of refrigeration systems with the rediscovered refrigerant carbon dioxide (CO2). A survey of the concept of an integrated on-board cooling system of airliners, the modelling language Modelica and the CO2-library is given and the modelling of CO2-heat exchangers is described. A comparison with steady state results of heat exchangers shows a fair agreement. The presented transient simulation results are compared with experimental data showing also a fair agreement.

The use of waste heat as an energy source for thermoelectric generation largely removes the constraint for the wide scale application of this technology imposed by its relatively low conversion efficiency (typically about 5%). Paradoxically, in some parasitic applications, a low conversion efficiency can be viewed as a distinct advantage. However, commercially available thermoelectric modules are designed primarily for refrigerating applications and are less reliable when operated at elevated temperatures. Consequently, a major factor which determines the economic competitiveness of thermoelectric recovery of waste heat is the cost per watt divided by the mean-time between module failures. In this paper is reported the development of a waste, warm water powered thermoelectric generator, one target in a NEDO sponsored project to economically recover waste heat. As an application of this technology case studies are considered in which thermoelectric generators are operated in both active and parasitic modes to generate electrical power for a central heating system. It is concluded that, in applications when the supply of heat essentially is free as with waste heat, thermoelectrics can compete economically with conventional methods of electrical power generation. Also, in this situation, and when the generating system is operated in a parasitic mode, conversion efficiency is not an important consideration.

Because the absorption refrigeration system uses the Lithium bromide- water solution as refrigerant, it is profitable for the environment that human beings are living since the values of ODP and GWP of the refrigerant almost are zero. However...

Sample records for heat commercial refrigeration from the National Library of Energy Beta (NLEBeta)

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As part of the effort to improve residential energy efficiency and reduce greenhouse emissions from power plants, several design options were investigated for improving the energy efficiency of a conventionally designed domestic refrigerator-freezer. The program goal was to reduce the energy consumption of a 20-ft{sup 3} (570-L) top-mount refrigerator-freeze to 1.00 kWh/d, a 50% reduction from the 1993 National Appliance Energy Conservation Act (NAECA) standard. The options--such as improved cabinet and door insulation, a high-efficiency compressor, a low-wattage fan, a large counterflow evaporator, and adaptive defrost control--were incorporated into prototype refrigerator-freezer cabinets and refrigeration systems. The refrigerant HFC-134a was used as a replacement for CFC-12. The baseline energy performance of the production refrigerator-freezers, along with cabinet heat load and compressor calorimeter test results, were extensively documented to provide a firm basis for experimentally measured energy savings. The project consisted of three main phases: (1) an evaluation of energy-efficient design options using computer simulation models and experimental testing, (2) design and testing of an initial prototype unit, and (3) energy and economic analyses of a final prototype. The final prototype achieved an energy consumption level of 0.93 kWh/d--an improvement of 45% over the baseline unit and 54% over the 1993 NAECA standard for 20-fg{sup 3} (570-L) units. The manufacturer`s cost for those improvements was estimated at $134; assuming that cost is doubled for the consumer, it would take about 11.4 years to pay for the design changes. Since the payback period was thought to be unfeasible, a second, more cost-effective design was also tested. Its energy consumption level was 1.16 kWh/d, a 42% energy savings, at a manufacturer`s cost increase of $53. Again assuming a 100% markup, the payback for this unit would be 6.6 years.

DOE ordered North Star Refrigerator Co., Inc. to pay a $8,000 civil penalty after finding North Star Refrigerator had failed to certify that any basic models of walk-in cooler and freezer components comply with the applicable energy conservation standards.

Superconducting tunnel junction detectors are being developed as both particle and X-ray detectors. Aluminum junctions are desirable for detectors because of their strong native oxide barriers, and because the small energy gap of aluminum is a good match to ballistic phonons generated by particle interactions in single crystals of silicon or other low acoustic-loss insulating crystals. Aluminum tunnel junction detectors must be operated near 0.1 T{sub C} which is 110 mK for aluminum. To operate detectors at these temperatures, we have developed adiabatic demagnetization refrigerators (ADRs) for the laboratory and prototype ADRs for space based operation. These cryogenic systems are simpler, more convenient and more portable than most dilution refrigerators. We have demonstrated that the magnetic field of the ADR need not compromise the performance of aluminum tunnel junctions. We have recently initiated a program to develop superconducting tunnel junctions (STJs) as high resolution X-ray detectors and low energy threshold particle detectors. This complements our existing program in which we are developing high resolution X-ray microcalorimeter detectors. One of our goals for both of these cryogenic detector development efforts is to observe X-ray emission from cosmic sources. This requires a refrigeration system that can operate under zero gravity space flight conditions. For the microcalorimeter project, temperatures of 100 mK and below are required to sufficiently reduce the heat capacity of the device. We have therefore developed an adiabatic demagnetization refrigerator (ADR) system which can be configured for space flight.

A hermetic refrigerant compressor having an electric motor and compressor assembly in a hermetic shell is cooled by oil which is first cooled in an external cooler 18 and is then delivered through the shell to the top of the motor rotor 24 where most of it is flung radially outwardly within the confined space provided by the cap 50 which channels the flow of most of the oil around the top of the stator 26 and then out to a multiplicity of holes 52 to flow down to the sump and provide further cooling of the motor and compressor. Part of the oil descends internally of the motor to the annular chamber 58 to provide oil cooling of the lower part of the motor, with this oil exiting through vent hole 62 also to the sump. Suction gas with entrained oil and liquid refrigerant therein is delivered to an oil separator 68 from which the suction gas passes by a confined path in pipe 66 to the suction plenum 64 and the separated oil drops from the separator to the sump. By providing the oil cooling of the parts, the suction gas is not used for cooling purposes and accordingly increase in superheat is substantially avoided in the passage of the suction gas through the shell to the suction plenum 64.

A hermetic refrigerant compressor having an electric motor and compressor assembly in a hermetic shell is cooled by oil which is first cooled in an external cooler and is then delivered through the shell to the top of the motor rotor where most of it is flung radially outwardly within the confined space provided by the cap which channels the flow of most of the oil around the top of the stator and then out to a multiplicity of holes to flow down to the sump and provide further cooling of the motor and compressor. Part of the oil descends internally of the motor to the annular chamber to provide oil cooling of the lower part of the motor, with this oil exiting through vent hole also to the sump. Suction gas with entrained oil and liquid refrigerant therein is delivered to an oil separator from which the suction gas passes by a confined path in pipe to the suction plenum and the separated oil drops from the separator to the sump. By providing the oil cooling of the parts, the suction gas is not used for cooling purposes and accordingly increase in superheat is substantially avoided in the passage of the suction gas through the shell to the suction plenum. 3 figs.

An assessment of several designs for gas engine-driven refrigeration systems for supermarkets is summarized. The objectives were to select the most viable alternative for a refrigeration system, to identify the potential market acceptance, and to define a feasible development and commercialization path for the most attractive system. The project included a telephone survey of supermarket engineering management to characterize current practices and equipment selection criteria, the development of preliminary designs for four principal system alternatives, and an evaluation of the economics of the system alternatives based on climate and energy rate data for Atlanta, Chicago, Los Angeles, and Phoenix. Of the four alternatives, one was unintegrated straight cogeneration and three were integrated cogeneration/refrigeration designs.

Experimental measurements are made for a silica gel-water advanced absorption refrigeration chiller (1.2-kW [4,095-Btu/h] cooling capacity) to evaluate its performance under different temperature and adsorption/desorption cycle time conditions. This paper describes the operating principle of the chiller, outlines the experimental hardware, and discusses results obtained by varying the cooling and hot water inlet temperatures and adsorption/desorption cycle times, as well as their agreement with the simulated results given by a lumped parameter model. The chiller performance is analyzed in terms of cooling capacity and coefficient of performance (COP). Excellent qualitative agreement was obtained between the experimental data and simulated results. The results showed the advanced three-stage cycle to be particularly well suited for operation with low-grade-temperature waste heat as the driving source, since it worked with small regenerating temperature lifts (heat source-heat sink temperature) of 10 to 30 K.

This report documents the energy consumption of commercialrefrigeration equipment (CRE) in the U.S. and evaluated the energy savings potential of various technologies and energy efficiency measures that could be applied to such equipment.

The influence of heat exchanger UA-values (adsorber/desorber, evaporator, and condenser) is investigated for an adsorption chiller, with consideration given to the thermal capacitance of the adsorber/desorber by means of a lumped-parameter cycle simulation model developed by the authors and co-workers for the single-stage silica gel-water adsorption chiller. The closed-cycle-type chiller, for use in air conditioning, is driven by low-grade waste heat (85 C [185 F]) and cooled by water at 31 C (88 F) and operates on relatively short cycle times (420 seconds adsorption/desorption; 30 second adsorber/desorber sensible cooling and heating). The results showed cycle performance to be considerably affected by the thermal capacitance and UA-value of the adsorber/desorber, which is attributed to the severe sensible cooling/heating requirements resulting from batched cycle operation. The model is also sensitive to the evaporator UA-value--but to a lesser extent. The condenser UA-value is the least sensitive parameter due to the working pair adsorption behavior in the temperature range defined for desorption and condensation.

and refrigeration systems. In many instances these real heat engines may appear as a complex process consisting of flash vessels, heat exchangers, compressors, furnaces, etc. See Figure 18a, which shows a simplified diagram of a "steam Rankine cycle." How... and rejection profiles of the real machine. For example, the heat acceptance and re jection profiles for the steam Rankine cycle shown in Figure 18a have been drawn on T,H coordinates in Figure 18b. Thus providing we know the heat acceptance and rejection...

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The report describes the feasibility study of several gas-fired refrigeration cycles using ammoniated complex compounds as the working media. The cycles take advantage of the coordinative characteristic of complex compound ligand bonds which result in large coordination spheres with only one degree of freedom. The coordinative bond yields refrigerant concentration plateaus of constant pressure, which in turn result in high thermal-cycle efficiencies and eliminate electrical parasitics and the requirement for moving parts. Media properties of known complex compound materials were verified with respect to vapor-pressure equilibria, coordination properties, and thermal stability. An existing computer model was used to predict heat balances and coefficients of performance.

Process Systems Engineering Optimal Synthesis of Refrigeration Cycles and Selection of Refrigerants, University Park, PA 16802 The optimal synthesis of the refrigeration configuration and the selection of the best refrigerants that satisfy a set of process cooling duties at different temperatures is ad- dressed

The EPA Refrigerator Analysis (ERA) program was utilized in the engineering analysis performed to support the proposed refrigerator/freezer standards in the United States. In this paper the accuracy of the ERA program for predicting the energy consumption of domestic refrigerators, freezers, and refrigerator-freezers is studied by comparing the predicted energy consumption with the measured energy consumption.

A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve. 4 figs.

A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve.

The Bonneville Power Administration (Bonneville) is conducting a large end-use data acquisition program in an effort to understand how energy is utilized in buildings with permanent electric space heating equipment in the Pacific Northwest. The initial portion of effort, known as the End-Use Load and Consumer Assessment Program (ELCAP), was conducted for Bonneville by the Pacific Northwest Laboratory (PNL). The collection of detailed end-use data provided an opportunity to analyze the amount of energy consumed by both refrigerators and separate freezers units located in residential buildings. By obtaining this information, the uncertainty of long- term regional end-use forecasting can be improved and potential utility marketing programs for new appliances with a reduced overall energy demand can be identified. It was found that standby loads derived from hourly averages between 4 a.m. and 5 a.m. reflected the minimum consumption needed to maintain interior refrigerator temperatures at a steady-state condition. Next, an average 24-hour consumption that included cooling loads from door openings and cooling food items was also determined. Later, analyses were conducted to develop a model capable of predicting refrigerator standby loads and 24-hour consumption for comparison with national refrigerator label ratings. Data for 140 residential sites with a refrigeration end-use were screened to develop a sample of 119 residences with pure refrigeration for use in this analysis. To identify those refrigerators that were considered to be pure (having no other devices present on the circuit) in terms of their end-use classification, the screening procedure used a statistical clustering technique that was based on standby loads with 24-hour consumption. 5 refs., 18 figs., 4 tabs.

A two-cycle 18 ft{sup 3} (0.51 m{sup 3}) refrigerator/freezer was tested utilizing American National Standards Institute/Association of Home Appliance Manufacturers (ANSI/AHAM) standards for energy consumption testing. A 34.9% energy consumption reduction was realized for a 1984 model refrigerator/freezer (1020 kWh original energy use). This paper presents a proven method of reducing the current Department of Energy (DOE) minimum energy-efficiency standards for refrigerator/freezers to the proposed year 2001 standards utilizing existing technology. For a top-mount, frost-free refrigerator/freezer having the above volume, the current DOE minimum energy standard is 770 kWh/year, and the proposed DOE year 2001 standard is 530 kWh/year (a 31% reduction). Therefore, some significant reductions may be obtained by implementing the modifications discussed in this paper into newer refrigerator/freezer models. The paper gives an overview of the modifications implemented by a Danish university on a US refrigerator/freezer and presents experimental performance testing results of the refrigerator/freezer. The modifications will cause the refrigerator/freezer to be more expensive, but the performance enhancements should offset cost. No cost analysis is presented in this paper, but a detailed cost analysis of a two-cycle refrigerator/freezer is contained in a 1993 US Environmental Protection Agency (EPA) report (EPA 1993). The refrigerator/freezer was tested using four refrigerants and compressors. Two compressors and refrigerants were tested in the freezer cycle, and four were tested in the fresh food cycle.

Thermodynamic cycles for natural gas liquefaction with single-component refrigerants are investigated under a governmental project in Korea aiming at new processes to meet the requirements on high efficiency large capacity and simple equipment. Based upon the optimization theory recently published by the present authors it is proposed to replace the methane-JT cycle in conventional cascade process with a nitrogen-Brayton cycle. A variety of systems to combine nitrogen-Brayton ethane-JT and propane-JT cycles are simulated with Aspen HYSYS and quantitatively compared in terms of thermodynamic efficiency flow rate of refrigerants and estimated size of heat exchangers. A specific Brayton-JT cycle is suggested with detailed thermodynamic data for further process development. The suggested cycle is expected to be more efficient and simpler than the existing cascade process while still taking advantage of easy and robust operation with single-component refrigerants.

In this work, the authors apply an equation of state based on statistical-mechanical perturbation theory to liquid refrigerants and their mixtures. Three temperature-dependent parameters are needed to use the equation of state: the second virial coefficient, B{sub 2}(T), an effective van der Waals covolume, b(T), and a scaling factor, {alpha}(T). The second virial coefficients are calculated from a correlation based on the heat of vaporization, {Delta}H{sub vap}, and the liquid density at the freezing point, p{sub fp}. {alpha}(T) and {beta}(T) can also be calculated from the second virial coefficient by a scaling rule. Based on the theory, these two temperature-dependent parameters depend only on the repulsive branch of the potential function, and therefore, by the procedure, can be found from {Delta}H{sub vap} and p{sub fp}. The theory has considerable predictive power, since it permits the construction of the p-v-T surface from the heat of vaporization plus the triple-point density. The equation of state is tested for pure, two- and three-component liquid refrigerant mixtures.

Small, Large, and Very Large Commercial Package Air Conditioners and Heat Pumps Small, Large, and Very Large Commercial Package Air Conditioners and Heat Pumps Sign up for e-mail updates on regulations for this and other products The Department of Energy (DOE) regulates the energy efficiency of small, large, and very large commercial package air conditioners and heat pumps. Commercial air conditioners and heat pumps are air-cooled, water-cooled, evaporatively-cooled, or water source unitary air conditioners or heat pumps that are used for space conditioning of commercial and industrial buildings. The standards implemented in 2010 for small and large, air-cooled commercial package air conditioners and heat pumps, and SPVUs, will save approximately 1.7 quads of energy and result in approximately $28.9 billion in energy bill savings for products shipped from 2010-2034. These standards will avoid about 90.3 million metric tons of carbon dioxide emissions, equivalent to the annual greenhouse gas emissions of 31.1 million automobiles. The standard implemented in 2010 for very large, air-cooled commercial package air conditioners and heat pumps will save approximately 0.43 quads of energy and result in approximately $4.3 billion in energy bill savings for products shipped from 2010-2034. The standard will avoid about 22.6 million metric tons of carbon dioxide emissions, equivalent to the annual greenhouse gas emissions of 4.4 million automobiles.

We present a simple mechanism for intra-molecular refrigeration, where parts of a molecule are actively cooled below the environmental temperature. We discuss the potential role and applications of such a mechanism in biology, in particular in enzymatic reactions.

DOE alleged in a Notice of Proposed Civil Penalty that Refrigerator Manufacturers, LLC failed to certify a variety of walk-in cooler or freezer components as compliant with the applicable energy conservation standards.

Sample records for heat commercial refrigeration from the National Library of Energy Beta (NLEBeta)

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A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

The objective of this paper is to describe salient features of a small refrigerator powered by a field of photovoltaic panels backed up by a petrol-start, kerosene-run portable generator set. Such units find applications in medical shops, veterinary applications and storage of vaccines in primary health centers. The modular arrangement allows use of certain components as a part of an uninterrupted power supply system for such refrigerators. Some preliminary results on temperature distributions and performance data are also presented.

Researchers from ARI member companies spoke at the International Conference on Alternative Refrigerants in Tokyo and visited several Japanese organizations for the purpose of exchanging information on alternative refrigerants. The specific purpose of the meetings was to review the methods being utilized to screen alternatives to CFCs and HCFCs: materials compatibility screening methods, lubricant testing techniques, as well as flammability studies. A list of papers presented at the conference is included.

A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

This project was initiated by the Department of Energy in response to a request from the HVAC industry for consolidated information about alternative heating and cooling cycles and for objective comparisons of those cycles in space conditioning applications. Twenty-seven different heat pumping technologies are compared on energy use and operating costs using consistent operating conditions and assumptions about component efficiencies for all of them. This report provides a concise summary of the underlying principals of each technology, its advantages and disadvantages, obstacles to commercial development, and economic feasibility. Both positive and negative results in this study are valuable; the fact that many of the cycles investigated are not attractive for space conditioning avoids any additional investment of time or resources in evaluating them for this application. In other cases, negative results in terms of the cost of materials or in cycle efficiencies identify where significant progress needs to be made in order for a cycle to become commercially attractive. Specific conclusions are listed for many of the technologies being promoted as alternatives to electrically-driven vapor compression heat pumps using fluorocarbon refrigerants. Although reverse Rankine cycle heat pumps using hydrocarbons have similar energy use to conventional electric-driven heat pumps, there are no significant energy savings due to the minor differences in estimated steady-state performance; higher costs would be required to accommodate the use of a flammable refrigerant. Magnetic and compressor-driven metal hydride heat pumps may be able to achieve efficiencies comparable to reverse Rankine cycle heat pumps, but they are likely to have much higher life cycle costs because of high costs for materials and peripheral equipment. Both thermoacoustic and thermionic heat pumps could have lower life cycle costs than conventional electric heat pumps because of reduced equipment and maintenance costs although energy use would be higher. There are strong opportunities for gas-fired heat pumps to reduce both energy use and operating costs outside of the high cooling climates in the southeast, south central states, and the southwest. Diesel and IC (Otto) engine-driven heat pumps are commercially available and should be able to increase their market share relative to gas furnaces on a life cycle cost basis; the cost premiums associated with these products, however, make it difficult to achieve three or five year paybacks which adversely affects their use in the U.S. Stirling engine-driven and duplex Stirling heat pumps have been investigated in the past as potential gas-fired appliances that would have longer lives and lower maintenance costs than diesel and IC engine-driven heat pumps at slightly lower efficiencies. These potential advantages have not been demonstrated and there has been a low level of interest in Stirling engine-driven heat pumps since the late 1980's. GAX absorption heat pumps have high heating efficiencies relative to conventional gas furnaces and are viable alternatives to furnace/air conditioner combinations in all parts of the country outside of the southeast, south central states, and desert southwest. Adsorption heat pumps may be competitive with the GAX absorption system at a higher degree of mechanical complexity; insufficient information is available to be more precise in that assessment.

This paper presents experimental results of the heat transfer performance of new egg-crate type evaporators that are becoming popular in vapor compression cycle-based modern refrigerators and freezers. These forced flow, multiple finned evaporators are preferred in the local industry over the older roll-bonded designs due to efficiency and cost considerations. Extensive testing was done, and experimental data were gathered on evaporators of three different sizes at three airflow rates using a closed-loop test rig built for the purpose. This has led to the development of a novel approach of measuring low air velocities as encountered in domestic refrigerators. A correlation has been developed for the heat transfer performance of these evaporators following the j-Colburn factor analysis. The correlation relates the j-Colburn factor, a nondimensional heat transfer grouping of the Nusselt number, Reynolds number, and Prandtl number to the Reynolds number and finning factor.

The Supermarket Energy Systems Project was structured to investigate and develop new highly energy-efficient supermarket refrigeration systems. A market and system analysis was performed for supermarket energy systems. The market analysis describes the overall structure of the supermarket industry as well as the distribution of energy-using systems in a typical supermarket. The market analysis evaluates the supermarket industry and the typical supermarket as customers buying energy-saving equipment. The systems analysis includes all supermarket energy-saving systems but focuses on the refrigeration system, the major energy-consuming system in a supermarket. A computer simulation program for supermarket refrigeration was developed and has been used to perform a sensitivity analysis, identifying those improvements or changes to the refrigeration system which offer the greatest energy-saving potential. Energy-saving improvements are described and evaluated. The results of the marketing and system analyses are combined with government, manufacturer, and customer criteria to rank various energy-saving improvements in order of desirability for further study, development and commercialization. A supermarket refrigeration system consisting of: unequal, parallel compressors; condenser with floating head-pressure control; and a microprocessor-based electronic control system was analyzed, designed, fabricated, and recommended. A compressor capacity control algorithm was designed to select the optimum compressor combination for each operating condition to match compressor capacity to refrigeration load. A microprocessor system based on an Intel 8085 microprocessor was selected for system control and data acquisition. An economic analysis was performed.

Air-Source Heat Pump Basics Air-Source Heat Pump Basics Air-Source Heat Pump Basics August 19, 2013 - 11:03am Addthis Air-source heat pumps transfer heat between the inside of a building and the outside air. How Air-Source Heat Pumps Work This diagram of a split-system heat pump heating cycle shows refrigerant circulating through a closed loop that passes through the wall of a house. Inside the house the refrigerant winds through indoor coils, with a fan blowing across them, and outside the house is another fan and another set of coils, the outdoor coils. A compressor is between the coils on one half of the loop, and an expansion valve is between the coils on the other half. The diagram is explained in the caption. In heating mode, an air-source heat pump evaporates a refrigerant in the outdoor coil; as the liquid evaporates it pulls

Source Heat Pump Basics Source Heat Pump Basics Air-Source Heat Pump Basics August 19, 2013 - 11:03am Addthis Air-source heat pumps transfer heat between the inside of a building and the outside air. How Air-Source Heat Pumps Work This diagram of a split-system heat pump heating cycle shows refrigerant circulating through a closed loop that passes through the wall of a house. Inside the house the refrigerant winds through indoor coils, with a fan blowing across them, and outside the house is another fan and another set of coils, the outdoor coils. A compressor is between the coils on one half of the loop, and an expansion valve is between the coils on the other half. The diagram is explained in the caption. In heating mode, an air-source heat pump evaporates a refrigerant in the outdoor coil; as the liquid evaporates it pulls

Small Business and Commercial Program Small Business and Commercial Program El Paso Electric Company - Small Business and Commercial Program < Back Eligibility Commercial Fed. Government Industrial Local Government Nonprofit State Government Savings Category Heating & Cooling CommercialHeating & Cooling Cooling Other Heat Pumps Appliances & Electronics Commercial Lighting Lighting Home Weatherization Insulation Design & Remodeling Solar Buying & Making Electricity Program Info State Texas Program Type Utility Rebate Program Rebate Amount Large Commercial Solutions: $240/peak kW demand reduction Small Commercial Solutions: $400/kW demand reduction Provider El Paso Electric Company El Paso Electric (EPE) offers several incentive programs targeting small business owners as well as larger commercial and industrial EPE customers.

Sample records for heat commercial refrigeration from the National Library of Energy Beta (NLEBeta)

Note: This page contains sample records for the topic "heat commercial refrigeration" from the National Library of EnergyBeta (NLEBeta).
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A five-watts G-M/J-T refrigerator was built and installed for the high-energy physics research at Brookhaven National Laboratory in 2001. A liquid helium target of 8.25 liters was required for an experiment in the proton beam line at the Alternating Gradient Synchrotron (AGS) of BNL. The large radiation heat load towards the target requires a five-watts refrigerator at 4.2 K to support a liquid helium flask of 0.2 meter in diameter and 0.3 meter in length which is made of Mylar film of 0.35 mm in thickness. The liquid helium flask is thermally exposed to the vacuum windows that are also made of 0.35 mm thickness Mylar film at room temperature. The refrigerator uses a two-stage Gifford-McMahon cryocooler for precooling the Joule-Thomson circuit that consists of five Linde-type heat exchangers. A mass flow rate of 0.8 {approx} 1.0 grams per second at 17.7 atm is applied to the refrigerator cold box. The two-phase helium flows between the liquid target and liquid/gas separator by means of thermosyphon. The paper presents the system design as well as the test results including the control of thermal oscillation.

Arcelik's Blomberg Refrigerator Arcelik's Blomberg Refrigerator DOE Closes Investigation of Arcelik's Blomberg Refrigerator September 1, 2010 - 4:37pm Addthis The Department of Energy has closed its investigation into the energy efficiency of Arcelik's Blomberg refrigerator-freezer model # BRFB1450. The Department opened this investigation based on a complaint. DOE subpoenaed information from Arcelik, reviewed Arcelik's response, and performed its own testing of this model. Based on our investigation and test results, DOE has determined this model to be compliant with federal energy conservation standards. Notice of Compliance Determination Addthis Related Articles DOE Opens Three Investigations into Alleged Refrigerator Efficiency Violations DOE Closes Investigation of Whirlpool's Maytag Refrigerator

High Efficiency Low Emission Supermarket High Efficiency Low Emission Supermarket Refrigeration Research Project High Efficiency Low Emission Supermarket Refrigeration Research Project The U.S. Department of Energy (DOE) is currently conducting research into high efficiency, low emission supermarket refrigeration technologies. Project Description The project involves the development of a supermarket refrigeration system that can reduce greenhouse gas emissions and energy consumption when compared to existing systems. The challenge is to design a system that is capable of achieving low refrigerant leak rates while significantly reducing both the energy consumption and the refrigerant charge size. Project Partners Research is being undertaken between DOE and Oak Ridge National Laboratory. Project Goals

UNDERGROUND GAS STORAGE CONCEPTS UNDERGROUND GAS STORAGE CONCEPTS REFRIGERATED-MINED CAVERN STORAGE FINAL REPORT DOE CONTRACT NUMBER DE-AC26-97FT34349 SUBMITTED BY: PB-KBB INC. 11757 KATY FREEWAY, SUITE 600 HOUSTON, TX 77079 SEPTEMBER 1998 Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily

Energy efficiency improvements in domestic refrigerator/freezers, are directly influenced by the overall thermal performance of the cabinet and doors. An advanced system for reducing heat gain is Gas-Filled Panel thermal insulation technology. Gas-Filled Panels contain a low-conductivity, inert gas at atmospheric pressure and employ a reflective baffle to suppress radiation and convection within the gas. This paper presents energy use test results for a 1993 model 500 liter top mount refrigerator/freezer operated with its original doors and with a series of alternative prototype doors. Gas-Filled Panel technology was used in two types of prototype refrigerator/freezer doors. In one design, panels were used in composite with foam in standard metal door pans; this design yielded no measurable energy savings. In the other design, special polymer door pans were fitted with panels that fill nearly all of the available insulation volume; this design yielded a 6.5% increase in energy efficiency for the entire refrigerator/freezer. The EPA Refrigerator Analysis computer program has been used to predict the change in daily energy consumption with the alternative doors. The computer model also projects a 25% energy efficiency improvement for a refrigerator/freezer that would use Gas-Filled Panel insulation throughout the cabinet as well as the doors.

The objective of the present study was to determine the performance of CO{sub 2} microchannel evaporators and gas coolers in operational conditions representing those of residential heat pumps. A set of breadboard prototype microchannel evaporators and gas coolers was developed and tested. The refrigerant in the heat exchangers followed a counter cross-flow path with respect to the airflow direction. The test conditions corresponded to the typical operating conditions of residential heat pumps. In addition, a second set of commercial microchannel evaporators and gas coolers was tested for a less comprehensive range of operating conditions. The test results were reduced and a comprehensive data analysis, including comparison with the previous studies in this field, was performed. Capacity and pressure drop of the evaporator and gas cooler for the range of parameters studied were analyzed and are documented in this report. A gas cooler performance prediction model based on non-dimensional parameters was also developed and results are discussed as well. In addition, in the present study, experiments were conducted to evaluate capacities and pressure drops for sub-critical CO{sub 2} flow boiling and transcritical CO{sub 2} gas cooling in microchannel heat exchangers. An extensive review of the literature failed to indicate any previous systematic study in this area, suggesting a lack of fundamental understanding of the phenomena and a lack of comprehensive data that would quantify the performance potential of CO{sub 2} microchannel heat exchangers for the application at hand. All experimental tests were successfully conducted with an energy balance within {+-}3%. The only exceptions to this were experiments at very low saturation temperatures (-23 C), where energy balances were as high as 10%. In the case of evaporators, it was found that a lower saturation temperature (especially when moisture condensation occurs) improves the overall heat transfer coefficient significantly. However, under such conditions, air side pressure drop also increases when moisture condensation occurs. An increase in airflow rate also increases the overall heat transfer coefficient. Air side pressure drop mainly depends on airflow rate. For the gas cooler, a significant portion of the heat transfer occurred in the first heat exchanger module on the refrigerant inlet side. The temperature and pressure of CO{sub 2} significantly affect the heat transfer and fluid flow characteristics due to some important properties (such as specific heat, density, and viscosity). In the transcritical region, performance of CO{sub 2} strongly depends on the operating temperature and pressure. Semi-empirical models were developed for predictions of CO{sub 2} evaporator and gas cooler system capacities. The evaporator model introduced two new factors to account for the effects of air-side moisture condensate and refrigerant outlet superheat. The model agreed with the experimental results within {+-}13%. The gas cooler model, based on non-dimensional parameters, successfully predicted the experimental results within {+-}20%. Recommendations for future work on this project include redesigning headers and/or introducing flow mixers to avoid flow mal-distribution problems, devising new defrosting techniques, and improving numerical models. These recommendations are described in more detail at the end of this report.